Tuatara
Victoria University College, Wellington, N.Z.
Vol. III. No. 1.Price—
One Shilling
May 1950
Contents
Editor:
Address Editorial correspondence to the Editor, Zoology Department, V.U.C.; advertising and subscriptions to the Publisher, Box 1580, Wgton.
W. R. B. Oliver
The fossil plant record of New Zealand is rather fragmentary. It does, however, show something of the kind of plants that succeeded one another in this region. Unfortunately the specimens from the oldest rocks in which plant remains have been found in New Zealand are too imperfect for identification but it is believed that the beds which contain them could be as old as the Carboniferous. From three localities in Canterbury and Otago a few species, moderately preserved, of a flora which can be classed as Rhaetic, are known. Except for three genera (Phyllotheca, Chiropteris, Baiera) characteristic of the Rhaetic, the plants are such as are found throughout the Triassic, Jurassic and early Cretaceous. With the much better known Upper Jurassic flora we have a group of Mesozoic plants that characterised a southern as opposed to a northern flora separated by an ocean bounding the north of Gondwana Land. In this flora members of the Gymnosperm families Araucariaceae and Podocarpaceae are characteristic and the presence of two species of Angiosperms has been proved. After an interval covering the first half of the Cretaceous we find bursting rather abruptly upon us a flora in which most of the characteristic Jurassic plants are absent, and, instead, Angiosperms are dominant. With them are the same families of Gymnosperms as were present in the Jurassic. This flora lasted until the Oligocene with important changes in that period. After another hiatus we find in the late Miocene a flora much like that of the present day and in the Pliocene floras still more modern in aspect.
Such, in brief, is the history of the succession of the floras that have existed in the past in the New Zealand region, a history that requires a continental connection to explain the presence of its main elements, more especially the group of gymnosperms. The degree of endemism in the present day flora, however, shows that New Zealand has been isolated for a very long time, probably for the whole of the Tertiary period.
The fossil flora of New Zealand, so far as it is known, must be taken into account when studying the origin of the present day flora. Comparisons of the early Tertiary floras of New Zealand and Australia show that the two were quite distinct, each having characteristics reminiscent of today's floras. But though the Tertiary flora of New Zealand developed into the present flora in isolation it received from time to time additions from Australia, presumably by some means of dispersal that carried plant disseminules across the intervening ocean. This seems a justifiable conclusion from the fact that there are some 300 species of plants in New Zealand indentical with Australian species. It is hardly believable that 300 species of flowering plants and ferns
Rhaetic Flora
A small flora consisting of 11 known species comes from Mount Potts, Clent Hills (Canterbury) and Owaka Creek. It is placed in the Rhaetic or uppermost Triassic because of the presence of three genera especially characteristic of the Triassic. These genera are Phyllotheca, an Equisetalian genus, Chiropteris, a fern-like plant, and Baiera, belonging to the Ginkgoales. Phyllotheca minuta, from Mount Potts and Clent Hills, is represented by detached whorls of leaves, about 10 in a whorl. Chiropteris lacerata, from Mount Potts, is a broad cuneate leaf with longitudinal parallel closely placed nerves frequently joining. Baiera robusta, from Mount Potts, is a fan-shaped leaf, slit longitudinally for half the length, with six or more of the basal parallel nerves extending into each segment.
Of the species found also in the Jurassic Linguifolium lillieanum deserves special mention. It is a spathulate leaf with a strong midrib from which arise, at a narrow angle, parallel nerves once or twice forked. Species of Linguifolium have been found in Rhaetic rocks in Chile and Australia. Cladophlebis is a genus of ferns with bipinnate leaves having oblong, acute and slightly falcate pinnae. C. australis has an almost world wide distribution from the Rhaetic to the end of the Jurassic. It is found in all the New Zealand Rhaetic localities. Cladophlebis is probably an Osmundaceous genus, at least the form of the petiolar bundles resembles those of the stems of Osmundites, so possibly the Cladophlebis leaves are the foliage of Osmundites though a direct connection has not been proved. Dictyophyllum is a fern having pinnatifid leaves with a pustular appearance over the whole surface. The sori are dispersed over the under side of the leaf. The New Zealand examples both in the Rhaetic and the Jurassic probably should be included in a single species, D. rugosum. Thinnfeldia is represented in the New Zealand Rhaetic by T. lancifolia, Mount Potts and Owaka Creek, and T. odontopteroides, Clent Hills and Owaka Creek. The forking of the veins of these two species is the basis of Gothan's genus Dicroidium but this classification was not accepted by Arber when he described the Mesozoic plants of New Zealand. In Thinnfeldia the leaves are pinnate, the pinnae being broadly ovate with a midrib and strong parallel secondary nerves arising at an acute angle. Sphenopteris is a genus of fern-like plants with compound leaves with free forking veins. Five species have been named from New Zealand, of which S. otagoensis and S. owakaensis from Owaka Creek are referred to the Rhaetic.
If the reference by H. H. Thomas of leaves of Taeniopteris to Williamconiella is justified then Taeniopteris, usually listed as a fern,
Taeniopteris has simple, lanceolate or spathulate leaves with strong midrib from which arise at right angles close parallel nerves single or once forked. Two species occur in the New Zealand Rhaetic, T. spatulata and T. thomsoniana. Of these T. spatulata is the most widely distributed. Elatocladus is the name given to coniferous twigs bearing small lanceolate leaves resembling those of Podocarps. E. conferta is found in the Rhaetic localities Mount Potts and Clent Hills, and in several Jurassic localities. Twigs of the Araucarian type with small leaves, named Brachyphyllum, have been found at Owaka Creek.
Jurassic Flora.
Plants of Upper Jurassic age have been collected in New Zealand principally in the following localities. Waikato Heads, Kawhia, Malvern Hills, Hokonui Hills, Mokoia (near Gore),
Cladophlebis is represented in the New Zealand Jurassic by the widely distributed and common C. australis and by C. denticulata and C. antarctica. As stated above the foliage Cladophlebis possibly belongs to the stems Osmundites of which two species, O. gibbiana and O. dunlopi (including O. aucklandicus) have been described from New Zealand. The fern Microphyllopteris pectinata bears rounded pinnules, 5-6 mm. across. It resembles in shape Cladophlebis reversa and better specimens are needed to define the difference. A beautiful fern with tripinnately divided leaves is Coniopteris hymenophylloides. In the fertile leaves the lamina is reduced and the sori are borne at the ends of the veins. The sori are partly enclosed in a cup-shaped indusium and the sporangium appears to be of the Cyatheaceous type. A second New Zealand species is C. lobata. Dictyophyllum rugosum is found at Linguifolium lillieanum at Malvern Hills, as well as at the Rhaetic localities already mentioned. A species of Thinnfeldia probably T. lancifolia, has been collected at Mokoia and Hokonui Hills. Sphenopteris gorensis and the allied Ruffordia goepperti occur at Mokoia.
Other Pteridophytes in the New Zealand Jurassic are two species of Equisetites and one of Lycopodites. These names denote species allied if not identical with the modern genera Equisetum and Lycopodium. E. hollowayi from Waikawa and Waikato Heads and E. nicoli from Mokoia are represented by whorls of acuminate leaves, those of E. nicoli being longer than those of E. hollowayi. Lycopodites arberi is a herbaceous species with undifferentiated ovate leaves. It was collected at Curio Bay, Waikawa.
There are about as many Gymnosperms as there are Pteridophytes in the Jurassic of New Zealand. Of the six species of Cycads Pterophyllum matauraensis has pinnate leaves, the pinnae being lanceolate, obtuse, and with conspicuous parallel nerves. Ptilophyllum acutilobum is also a pinnate form but the pinnae are narrow, acuminate and falcate. It has been found at Waikawa. In Nilssonia the leaf is narrow, broadest near the apex, with parallel veins arising from the midrib and with unequal-sized lobes. The two New Zealand species are. N. compta from Waikawa, deeply cut between the relatively narrow lobes, and N. elegans, from Nilssonia recall those of Taeniopteris. Taeniopteris, possibly a Cycad, is represented in the Jurassic of New Zealand by the large and broad-leaved species T. crassinervis from T. spatulata, generally distributed; and by T. vittata, at Waikawa but doubtfully distinct from T. spatulata.
The family Araucariaceae, to which the present day Norfolk Island pine belongs, seems to have been well represented in Jurassic times. Leaves, cone scales and wood are present in the New Zealand rocks and are referred to five genera, but in life these might represent two or three species. This is because palaeobotanists have to give a generic name to each part of the plant as they are unable to prove which parts make up any particular species. Shoots with small leaves from Pagiophyllum. Large linear-lanceolate leaves are known as Podozamites. Two species, P. gracilis from Waikawa, and P. lanceolatus from Waikato Heads, are known. Cone scales are referred to Araucarites, those from Mokoia being named A. cutchensis and those from Waikawa, A. grandis. Dadoxylon australae from Waikawa is a wood of Araucarian type.
Jurassic conifers other than of Araucarian affinity include the cone Palissya bartrumi from Waikawa. This is an elongated cone with the scales loosely arranged when mature. It is possible that one of the species of Elatocladus represent the foliage belonging to these cones.
The last species belonging to the Jurassic of New Zealand to be mentioned is the Angiosperm Artocarpidium arberi. This was found at Waikato Heads on the same rock as the typically Mesozoic fern Cladophlebis australis. Because of the presence of this dicotyledonous plant Arber referred the beds to the Neocomian, that is, to the lowest Cretaceous, but Edwards thinks that the Waikato Heads beds would better be placed in the Upper Jurassic. Artocarpidium arberi is represented by two leaf impressions. These have the appearance of European beech leaves in which the marginal teeth are little developed. The straight parallel secondary nerves reaching the leaf margin especially recalls the beech family.
Concerning the relationships of the Jurassic flora of New Zealand Edwards says that about half the species have been recorded from
The Jurassic flora is essentially different from the Cretaceo- Tertiary floras though no doubt many of the ferns and gymnosperms of the Cretaceo-Tertiary are direct descendants of Jurassic genera. After the Jurassic there is a long gap in the New Zealand record and the next plant bearing beds, Upper Cretaceous, are dominated by true flowering plants.
Cretaceous Flora
The early Mesozoic floras are much more uniform throughout the world than are the floras from the Middle Cretaceous and onwards which are dominated by Angiosperms. In the Upper Cretaceous distinct plant provinces have come into existence, the flora of the New Zealand province, for instance, being almost as different from that of the Australian province as it is today. Surviving from Jurassic times there are in the Cretaceous flora ferns and gymnosperms but they are dominated by Angiosperms thus contrasting with the Jurassic flora where fern-like plants are dominant. The podocarps and araucarians are the characteristic gymnosperms in the southern floras both in the early Mesozoic and the Cretaceous as in fact they are at the present day.
The earliest Cretaceous plant bearing beds are found in the Paparoa coal measures in the Greymouth district. In these beds there occur such typically Mesozoic species as Coniopteris hymenophylloides and Cladophlebis denticulata together with a fern of more modern appearance, Pteris, a Gymnosperm like Podocarpus and several species of Angiosperms. This assemblage of plants indicates a middle or early Cretaceous date.
Quite different from the Paparoa flora and apparently of considerably later date is the Cretaceous flora at Shag Point. This flora has much in common with those at Pakawau and Wangapeka (Nelson) here classed as Eocene, several genera and species being common to two or more of these flora. A fern Cyclosorus tertiarozeelandicus, is found at Shag Point and is closely related to another species from Pakawau.
The gymnosperms of the New Zealand Cretaceous belong mainly to two families, Araucariaceae and Podocarpaceae. The Araucarians are referred to the genera Agathis and Araucaria. Three species from Shag Point were named and figured, but not described, by Hector in 1886. They are Araucaria buchanani, A. carinaria, and Agathis lanceo-
latus and to these may be referred, five species described by Ettingshausen. in 1887. Hector's names are accepted as valid. Araucaria buchanani has small leaves somewhat like those of the Norfolk Island pine. A. carinaria has large leaves more or less triangular in section hence the specific name referring to the central ridge. Agathis lanceolata has large flat leaves similar to those of the kauri. A species with broadly ovate leaves, Agathis marshalli, has recently been described from the Kaipara district in beds of Upper Cretaceous age.
The Podocarps from Shag Point include Dacrydium praecupressinum (also from Pakawau), and two species of Podocarpus both found at Pakawau as well. Athrotaxis novazeelandiae, from Shag Point, has Cypress-like leaves and globose cones. Athrotaxis belongs to the family Taxodiaceae and at the present day is found only in Tasmania. The family includes the giant species of Sequoia of California.
Some Angiosperms from Shag Point which have received names and can with some degree of confidence be classified are mentioned below.
Cinnamomum is the name given to leaves having three principle nerves near the base, the next prominent secondaries arising some distance up the midrib. C. intermedium from Shag Point has rather large oblong leaves.
Nothofagus was in the Cretaceo-Eocene represented by several species with larger leaves than those belonging to living New Zealand species of the genus. It is impossible to say that the leaves definitely belong to Nothofagus, and not to Fagus, but as Fagus is not now found in New Zealand it will be convenient to group the New Zealand fossil forms under Nothofagus. N. lendenfeldi from Malvern Hills, an Upper Cretaceous locality, has leaves with the base truncate and the secondaries parallel and reaching the margin which is finely serrate. N. ulmifolia, from Shag Point, has close parallel secondaries and a finely denticulate margin. Leaves of N. ninnisiana, described by Unger from the Oligocene of the lower Waikato district, are hardly distinguishable from leaves found at Shag Point, Pakawau and Wangapeka.
To find an existing flora that, like the Shag Point flora, contains Podocarps, deciduous trees and evergreen trees one must go to the mid-mountain zone in New Guinea. In the Cretaceous there may have been a closer affinity between the floras of the New Guinea and New Zealand regions, and possibly since that time the deciduous element in the New Zealand flora has become extinct. It is difficult to see a cause for such a change. One would think that a general cooling of the climate in New Zealand, as has taken place since the mid-Tertiary, would have the opposite effect.
Acer tasmani from Shag Point was described by Ettingshausen as an Aralia but obviously he was dealing with a leaf impression broken
Acer. In any case it shows more resemblance to present day northern hemisphere deciduous trees than it does to any recent New Zealand species. Acer subtrilobatum, from the same locality, is a similar type of leaf. Unfortunately an impression of only a portion of a leaf is preserved.
Eocene Flora.
The plant beds at Pakawau, Wangapeka, Dunstan and Trelissick Basin may be classed as Eocene. These floras have much in common with each other and with that at Shag Point, and like it consists of ferns, conifers and Angiosperms, the latter including trees of both a deciduous and evergreen appearance.
The ferns described from Pakawau can all be referred to recent genera. They are Blechnum priscum, Cyclosorus cretaceo-zeelandicus, Sticherus obscurus, and Pteris pterioides. The Conifers are Agathis lanceolata, Dacrydium praecupressinum, Podocarpus cupressinum, P. maitai, P. parkeri and P. praedacrydioides.
In 1886 Hector named and figured, from Pakawau, a large, ovate, finely serrated leaf, Patete schefleri. This name can be accepted as no modern genus of New Zealand plants would include it. It has, however, no claim to be considered an araliad as both generic and specific names would seem to imply. More likely it belonged to the Tiliaceae. Ettingshausen's Grewiopsis pakawauica is apparently the same species.
Cinnamomum is represented at Pakawau by C. haastii, a species with small oval leaves. Haastia speciosa, from Pakawau, is a very large, broad leaf like that of a banana. Probably it indicated a warm climate at the beginning of the Tertiary period.
At Wangapeka in the Nelson district there occur some ferns, not yet described, Podocarpus trinervia, resembling the recent P. totara and two species of Phyllocladus. P. tanekaha recalls the mountain toatoa; but P. toatoa is quite different having veins occasionally joining together. There are leaves of Araucaria and several species of Angiosperms at Wangapeka, but no description of them has been published. There is a broad-leaved species of Cinnamomum, a narrow-leaved species of Nothofagus, a three-lobed leaf like the tropical genus Sterculia and leaves resembling those of Aristotelia and Melicytus.
Dryandra comptoniaefolia, from the Trelissick Basin, is an elongate, pinnatifid leaf with the segments having one to three nerves arising from the midrib. This is an interesting record, probably correct, as better preserved examples of this genus occur in the Australian Tertiary. Potamogeton ovatum, from the Trelissick Basin, has oval leaves with the characteristic nervation of the genus but it is not conspecific with any recent New Zealand species.
Oligocene Flora.
Plants of this age are known from Landslip Hill and Ohai in Southland and from the lower Waikato district. At Landslip Hill the leaf impressions, in several cases with the nervation preserved in great detail, are on quartzite. These beds are apparently older than those at Ohai and the Waikato. The most conspicuous species at Landslip Hill is Pittosporum elegans, a large-leaved form resembling the recent P. colensci. There are species of Carpodetus, Pomaderris, Araucaria and Dacrydium. Most remarkable, however, is a fern that recalls Linguifolium. It is a large leaf with midrib and parallel unbranched lateral nerves arising at acute angles.
At Ohai there are large leaves of the types of Acer, Castanea and Cinnamomum, relics, as it were, of the Cretaceo-Eocene flora, and there is an Araucaria or Agathis. But with these are leaves of more modern aspect recalling Rubus, Clematis and Hoheria.
The Waikato flora has been described by Unger and by Penseler Unger described an elongate, tongue-shaped leaf with a clasping bas under the name Myrtifolium lingua. It might be a Euphorbia similar to E. glauca. He also described Fagus ninnisiana, a large leaved species which would more conveniently be classed, under Nothofagus. From Pukemiro Penseler records species of Geniostoma, Beilschmiedia and Coprosma, thus showing the close affinity of the Oligocene flora to that of the present day.
Legends to Figures
Miocene-Pliocene Floras.
We have no knowledge of what kinds of plants existed in New Zealand during most of the Miocene period; for it probably was at the end of the Miocene that the plant bearing beds at Whangaroa and Wharekuri were laid down. At Whangaroa the few plants preserved are for the most part like those of the Pliocene and the present day. A well-preserved leaf is quite similar in appearance to Griselinia. Other impressions remind one of the leaves of Pittosporum, Brachyglottis and Cyathodes. Similarly at Wharekuri leaf impressions that could be classed as Pittosporum and Coprosma are found.
From the Pliocene two floras have been described, both preserved in fine volcanic tuffs. The flora of the Kaikorai Valley includes representatives of 19 genera of which possibly three are not now found living in New Zealand, namely, Parafagus, Patete (equals Ulmophylon) and Kaikoraia. Well knows recent genera like Laurelia, Coriaria, Metrosideros, Coprosma, Senecio and Knightia, occur. The Waipaoa flora from the Poverty Bay district consists almost entirely of recent New Zealand genera. Of 30 genera only two, Platycerium and Apocynophyllum?, are not now found in New Zealand. Characteristic New Zealand genera found at Waipaia are Carmichaelia, Rhopalostylis, Plagianthus, Hebe, Coprosma, Paratrophis and others.
Legends to Figures
The illustrations have been from the following sources: Nos. 14, 15, 29-30 original; Nos. 1-3, 8-10, 12 after Arber; Nos. 4-7, 11, 16-18, 25, after Buchanan (ined.); Nos. 19-24, 27 after Ettingshausen (Trans. N.Z. Inst. Vol. 23); Nos. 26, 28 after Unger; No. 13 after Edwards.
,D. Spiller
Plant Diseases Division, Department of Scientific and Industrial Research
The insects which destroy seasoned timber comprise two major groups, termites and beetles. This account is confined to the beetles.
All beetles have indirect development with four distinct stages in the life history, egg, larva, pupa and adult. The adults are free living, with biting mouth parts. The antennae are usually well developed and elongate. Beetles are hard bodied and it is characteristic that the first pair of wings are heavily chitinised to form elytra, which cover the membranous second pair of wings and enclose and protect the upper surface of the abdomen.
One of the pecularities of wood as an environment and substrate is the absence of free water. The relatively small amounts (10-25 per cent.) of bound water are available to the insect only when the wood is digested. Wood is compact and since relatively little is digested by the insect, the energy gained on digestion is small relative to the amount expended in removing pieces from the compact substratum. The nitrogen content of wood is very low (approximately 0.2 per cent.) and much wood must be consumed to obtain sufficient protein for growth from egg to adult. These peculiarities are reflected in the life cycle which is prolonged even under the optimum conditions of humidity and temperature. Presumably it needs a long life cycle to accumulate sufficient water, energy and protein for growth to maturity.
In addition to the lengthy life cycle, there is a common core of biology applicable to all timber beetles. In every case the entire life of the larvae is spent tunnelling within the timber. When the grub is mature it approaches the surface and forms a cell in which pupation occurs. When the pupal period has elapsed, the adult hardens for a few days within the cell and then cuts its way to the wood surface. The holes made in this way are known as exit holes and generally their size and shape are characteristic of the species which makes them. Mating occurs on the surface of the wood and usually occurs several times during adult life. The adults live only a few weeks and during this period females lay eggs either in cracks and crevices on the wood surface, or, in Lyctids, in the pores (vessels) of the wood. The average number of eggs is usually less than 100 and in no case is it exceedingly large.
The eggs hatch in from one to three weeks and special conditions are not required, hatching occurring at most normal conditions of temperature and humidity. The young larvae bore through the egg
The various species are each attacked by one or more species of parasites, but unless the infestation is old, percentage parasitism is so low that it is of no importance in controlling the infestation. Once a piece of timber becomes infested it is reinfested with each succeeding emergence of beetles and the population increases until in extreme cases the timber is destroyed.
The beetles which attack seasoned timber in New Zealand can be divided into four sub-groups within which behaviour and biology is similar. The four sub-groups, in order of economic importance, are the Anobiidis, the longhorns, the Lyctids and the cossonid weevils. Each will be discussed in turn.
The Anobiids (Anobium and related genera). Everyone is familiar with “the borer” better called the common house borer, Anobium punctatum De. G., which is not a native of New Zealand and occurs in most parts of the world. It is the most important and wide-spread of the beetles which attack sound seasoned timber in this country. Only the sapwood is attacked and none of the New Zealand timber species appears to be immune. Infestation can occur as soon as the timber is air dry (i.e., less than 30 per cent. moisture). When timber becomes infested for the first time, the attack is not apparent until exit holes appear, by which time one life cycle has already elapsed. Since the initial infestation is usually slight, two and even three generations may be completed before the infestation is noticed and such observations appear to be the origin of the popular belief that timber is not liable to infestation for 5-15 years after it has been milled.
The beetles are small (3-5 mm.), relatively inactive and may often be found in considerable numbers on the surface of infected timber during the period of emergence, which in Auckland extends from October to the end of January. However, the main emergence covers five weeks from the beginning of December with a maximum emergence around the middle of that month. Although there is an annual flight the life cycle is at least three years, while in some timbers six years may elapse between the time eggs are laid and beetles emerge. Thus the annual flight indicates a series of overlapping generations, not a one year life cycle. The eggs are laid either on rough surfaces of the wood or within the pupal cells at the base of the exit holes and are firmly attached to the wood surface. The number of eggs laid
Little is known of optimum temperature or wood moisture content for larval growth, but larvae survive and grow well at a constant temperature of 22.5 deg. C. with relative humidity of 85 per cent. and these conditions are used for most tests.
The common house borer has some allies, less important but occasionally met with. In the South Island, and as far as is known not occurring in the North Island, there occurs a native and as yet undescribed species of Xyletinus which is responsible for a good deal of so called “borer” damage at least in older buildings. It is widespread and has on occasion caused severe damage to buildings. Exit holes are of almost the same size and shape as those of Anobium punctatum, while the flight periods are also roughly coincident.
An endemic and much larger beetle Anobium magnum Dumbl. occurs not infrequently in decayed boards throughout the country. The exit holes are larger than those of Anobium punctatum and usually there are but few on each board. Although damage is both intensive and extensive, the presence of this insect always indicates decay due to free water or abnormally high atmospheric humidity. Elimination of the decay hazard by adequate ventilation and/or removal of the source of free water eliminates this insect.
The introduced pine borer, Ernobius mollis L. has been present for many years, but has not become a serious pest. This species attacks only the sapwood of pine (Pinus sp.) but cannot infest a board unless there is bark adhering to the wood. When bark is present infestation can be severe. Prevention of attack results from removal of all traces of bark.
Two other species are occasionally collected from infested timber and from houses. These are Capnodes griseipilus Broun, and Dorcatoma oblonga Broun, both natives of New Zealand. Nothing definite is known of their biology, but it is thought that they breed in decayed wood. They have no economic significance.
The Longhorns: The two toothed longhorn, Ambeodontus tristis F. is second only to the common house borer in the severity of its attack on building timbers.
The length of the life cycle is unknown and estimates range from two to seven years or more and these are probably correct, larvae reaching maturity within a year or two under optimum conditions, while under adverse conditions the life cycle is prolonged. The emergence period does not appear to be well defined and although it probably reaches a maximum during May and June isolated adults may be found throughout the year. The adults are variable in size, females measuring from 8-22 mm. in length, while the males are less variable and are never as large as the largest females.
Females die rapidly and do not lay eggs under the normally somewhat dry conditions of the laboratory. Under saturated conditions females survive well and deposit all their eggs. However, saturation is not essential and at humidities of 95 per cent. and above all the eggs are laid while at humidities below 92 per cent, few eggs are produced (at 23 deg. C.). Females do not lay eggs on the normal surfaces of wood blocks, but if egglaying sites 1/32 inch wide and 1/16 inch deep and long are made on the relatively smooth block surfaces, females lay usually one, but sometimes two and rarely more eggs in each site. The eggs hatch well under all normal conditions. The number of eggs laid by each female varies according to size and in the few females studied, the smallest produced 28 eggs, the largest 239 eggs. The average length of the females was 14.2 mm. and the average eggs 97.
The Lyctids: (Lyctus and related genera). This group of beetles, commonly termed powder post beetles or borers, are pests in all parts of the world where sapwood of hardwoods (i.e., wood from broad-leaved trees) is used. There are no species native to New Zealand. Of the many species known as pests Lyctus brunneus Steph. is most abundant in New Zealand and is perhaps the only species which has established. Occasionally other species are found infesting furniture and packing boxes, but usually the circumstances indicate that infestation occurred in another country and that the article was infested when imported; as examples, L. linearis (Goeze) has been found infesting an oak table from England; L. planicollis (Lec.) infesting hickory axe handles from the United States of America and Trogoxylon inequale Woll. infesting a wood toy from Trinidad. Likewise packing cases and wooden objects from most parts of the world arrive in New Zealand and are sometimes found to be infested with L. brunneus.
Most of the commercial timbers used in New Zealand (rimu, matai, kahikatea, exotic pinus, Pinus ml, etc.) being soft woods, are immune from attack by powder post beetles. Of the native hardwoods both the beeches (Nothofagus sp.) and ratas (Metrosideros sp.) are little attacked although some beeches are known to be susceptible at times. However, sapwood of tawa (Bielschmieda tawa) is so susceptible to attack that the increased utilisation of this species depends almost entirely on control of this beetle.
Only sapwood is attacked. However, the sapwood of some hardwood species is not attacked and it is also common to find amongst susceptible species, e.g., tawa, that some boards will be attacked while others—perhaps even from the same tree—remain free of infestation. Females lay their eggs in the pores (vessels) of the wood. When these are very small (maximum size less than 0.0035 inch in greatest width) eggs cannot be inserted into the pores. Thus pore size and absence of pores explains why some hardwood species and all soft woods are immune from attack. The major food of Lyctus larvae is
The length of life-cycle varies considerably according to climate: under optimum conditions it may be as short as three months, but under natural conditions a generation a year is normal.
Eggs are laid as soon as the wood surfaces are air dry and very little susceptible sapwood escapes attack for more than one-two years after milling. Boards frequently become infested in timber yards and stacks and because the initial stages of attack are not obvious, infested wood is often used for making furniture and doors, without the infestation being detected. Up to twelve months later, exit holes, sometimes in great numbers, appear on one or more boards and unless the attack is arrested these boards will be completely destroyed in from two to four years. This rapidity of destruction is an important distinction between Lyctus and other timber beetles. For instance with Anobium much timber is infested for from 15-30 years before the strength is much impaired; with Lyctus complete destruction of susceptible timber seldom takes more than three years.
The cossonid weevils: (Torostoma apicale Br., related genera and species). This is the least important sub-group of the timber insects. Attack is confined to sapwood, and while damage can at times be severe, usually it is associated with or follows decay. Not infrequently these weevils attack wood that has been severely infested with Anobium and it is thought that Anobium attack has opened up the timber, permitting access of water with subsequent decay and weevil attack. In the few cases in which apparently sound timber has been attacked — and this is usually flooring or subfloor—atmospheric humidity was high due to inadequate ventilation.
Although there is a good general knowledge of most aspects of the biology of the timber attacking beetles of major importance, one problem and that perhaps the most important remains untouched. Almost nothing is known of the nutrition of these insects, or of the factors governing susceptibility of various timber species and contributing to susceptibility variation within and between boards of the same species.
It is known that starch is an important factor in determining whether sapwood of hardwoods is attacked by Lyctus, but equally it is realised that this is not the full picture. On occasion boards with heavy starch deposits remain immune to attack or are damaged but lightly. It is often stated—presumably by analogy with Lyctus—that presence or absence of starch and free sugar determines whether or not a board will be attacked by the common borer Anobium punctatum. While it is certain that this is incorrect it is not known which component of the wood is digested by Anobium larvae or indeed how
Similarly there is little information on the factors which govern susceptibility of boards to attack, but it is now recognised that some sapwood boards of all species of timbers, including the very susceptible timbers kahikatea and matai are immune from Anobium attack and are therefore to be regarded as non-susceptible. Detailed investigation of the allied problems of larval nutrition and wood susceptibility is very necessary and when this knowledge becomes available most of the remaining and foreseeable problems in the biology of the New Zealand timber beetles will be capable of solution. Perhaps detailed knowledge of these problems will point the way to the possibility or otherwise of preventing attack other than by the use of chemicals. Because of the importance of these problems it is proposed to reorient the timber work at this Division and concentrate on nutrition and susceptibility coming back to other outstanding problems only when this information is available.
It is the damage done by timber insects that has focussed attention upon them and the objective of all the research is prevention of this damage. In the control of timber insects there are two problems, one the treatment of wood to prevent attack, the other treatment of buildings and structural timber to eliminate insects which are already there. It is usual to designate these problems as pretreatment and eradication.
Consider first pre-treatment. Here also are two problems distinct in approach and methods. Firstly to determine what materials are sufficiently toxic to the insect to be worthy of use against them and secondly the experimental operation of pilot treating plants to ascertain how best to treat timber with these materials. This second aspect does not deal with insect biology or with toxicity of materials to insects and will not be dealt with here.
Relatively simple methods are now available for determination of toxicity of materials. Small blocks of wood (approximately one inch cubes) are impregnated with chemicals under conditions which ensure complete penetration and uniform distribution of the material to be tested. The impregnated blocks are allowed to dry and are then placed in cages in the testing room, where sufficient Anobium females are introduced to ensure oviposition of more than 150 eggs. The blocks are stored for about nine months under conditions known to be suitable for development of Anobium larvae. At the end of this period each block is sectioned on a microtome and presence or absence of larvae determined. By employing a series of concentrations of preservative from very low to high it is possible to determine for each
Anobium larvae even when present to the extent of two per cent. of the weight of the wood.
The figures given by the above method of testing toxicity apply only when the timber is completely penetrated by preservative, a requirement which, although good practice, necessitates the use of relatively expensive treating plants. Because of this, treating cannot be carried out other than on an extensive scale. This means that those wishing to use pre-treated timber, must buy it already treated. There are other methods of treating timber which have been extensively used and widely recommended that do not suffer this disadvantage. Mostly these involve dipping dry timber in solutions of preservatives in petroleum oils. For various reasons these methods are not satisfactory.
For most people, the major interest in timber insects is not insect biology or treatment of timber to prevent attack, but eliminating or reducing an attack in a house or wooden structure. The methods available comprise two operations which may be used separately, but normally are used in conjunction. Treating material is dissolved in a carrier or solvent (kerosene, mineral turpentine, diesel oil, etc.), and the solution injected into the timber with a pressure gun. After all exit holes have been treated the available surfaces of the timber are sprayed or brushed with the solution used for injection. Since it is impossible to obtain complete penetration of treating liquid only population reduction and not eradication is to be expected with these methods unless the treating liquid contains a residual contact insecticide.
When a treating liquid containing a residual contact insecticide is used, a film of insecticide is left which may either kill the beetles when boring their exit holes or after they have emerged and before eggs are laid. Because the life cycle of Anobium is at least three years the well known contact insecticides (e.g., D.D.T., Gammexane) may not be suited to this purpose as their films usually lose effectiveness within a few weeks or months of application. With such materials it would be necessary to spray prior to the flight in each year making the cost prohibitive. If, however, a potent contact insecticide, effective for at least three years can be found, economic control of infestations will be assured.
Wood is a very variable material and when it is infested with insects the extent of infestation is another variable. It is relatively easy to obtain good control (i.e., with kerosine, mineral turpentine or
Because of this variation no two tests can be expected to give identical results and no material behaves consistently as far as percentage control is concerned. However from these tests, a pattern of effects is gradually built up which helps in understanding and therefore in solving the problem. When this pattern is clear and the types of action of the various materials and the mechanics of the problem are clearly understood, it will cease to be of laboratory interest and must be taken into the field for further trial and evaluation of both methods and materials.
This review is based on work carried out at the Plant Diseases Division during the last ten years. Much of the work is as yet unpublished. Those interested in types of damage and recognition of the insects concerned should refer to “Insects attacking milled timber, poles and posts in New Zealand” by J. M. Kelsey, N.Z. Journ. Sci. & Tech. 28 (Sec. B) 65-100, Recent volumes of the same journal should be consulted for further details on insect biology and control, on preservative pre-treatment of timber, or toxicity of various chemicals to wood destroying fungi. It is anticipated that many papers on these allied problems will be published in that journal during the next few years.
Acknowledgments
The editorial committee has much pleasure in acknowledging financial assistance from the Publication Fund of Victoria University College, towards the cost of printing this number of “Tuatara”.
, Wairoa, Hawke's Bay.E. Amy Hodgson
With a Key to the New Zealand Genera
The Hepaticae or liverworts form the second of the two classes into which the Bryophyta are divided. The two main distinctions between the classes are said to be, that of the liverworts have unicellular rhizoids, and spiral elaters mixed with the spores in the capsules (except in Ricciaceae). The non-thalloid or foliose hepatics differ from the mosses, generally speaking, in the following respects; in the rudimentary and short-lived protonema; in the bi-lateral leaves always without a midrib, and frequently bilobed; in the usual presence of stipules; in the capsule remaining in the more or less delicate calyptra (destitute of lid) till the spores are mature, then developing a hyaline and evanescent, sometimes elongated seta, and commonly dehiscing by four valves, peristome always absent. Generally speaking, the liverworts prefer wetter conditions than the mosses.
Probably the earliest collection of New Zealand hepatics was that of Archibald Menzies, gathered at Dusky Sound in 1791. These were described and figured by Sir William Hooker in his Musci Exotici in 1818. Sir Botany of the Antarctic Voyage, in several volumes spread over many years, contains the descriptions of plants collected by Hooker in the subantarctic islands, Northland (N.Z.), and Tasmania, together with many of Colenso's. Dr. T. Taylor and W. Mitten were responsible for these descriptions. In 1867, Part II of Hooker's Handbook of the New Zealand Flora was published, a portion of which is devoted to the liverworts, with an Appendix by Mitten. Dealing with plants collected by the earlier botanists, the Handbook has been the basis of all our work on New Zealand Hepaticae. Stephani's famous Species Hepaticarum in 6 volumes, 1900-1924, includes descriptions of all New Zealand species to date. Local Floras of both hemispheres are useful for obtaining information about hepatics, the handiest, perhaps, being L. Rodway's “Tasmanian Bryophyta II, Hepatics.”Papers & Proc. Roy. Soc. Tasmania 1916.
The system of classification used in this paper, is that set out by Evans. Evans, A. W., 1939. Classification of the Hepaticae, Botanical Review, vol. 5, p. 20.
Three of the four orders of the Hepaticae are represented in New Zealand.
Jungermanniales
Plants both foliose and thalloid, the latter not differentiated into layers of different tissue and without pores. Tuberculate rhizoids not present. Sexual organs usually in groups, but not on special pedunculate receptacles. Capsule, usually on a long seta, opening by 4 valves. Apical growth of stem or thallus proceeds from a single cell.
-
Sub-order 1 Haplomitrineae
- Family Haplomitriaceae,
Calobryum.
-
Sub-order 2 Jungermannineae (Jungermanniales acrogynae)
- Family Ptilidiaceae,
Herberta, Mastigophora, Hygrobiella, Ptilidium, Bleoharostoma, Isotachis, Lepicolea, Lepidolaena, Trichocolea. - Family Lepidoziaceae, Bazzania. Acromastigum, Psiloclada, Lepidozia.
- Family Cephaloziaceae, Cephalozia, Lembidium, Zoopsis, Adelanthus, Marsupidium.
- Family Cephaloziellaceae,
Cephaloziella. - Family Harpanthaceae, Lophocolea, Chiloscyphus, Mylia, Geocalyx, Saccogyna.
- Family Jungermanniaceae,
Lophozia, Sphenolobus, Anastrophyllum, Cuspidatula, Chandonathus, Jungermannia, Jamesoniella, Acrobolbus, Symphyomitra. - Family Marsupellaceae,
Gymnomitrium. - Family Plagiochilaceae,
Plagiochila, Tylimanthus. - Family Scapaniaceae,
Diplophyllum. - Family Schistochilaceae,
Schistochila, Balantiopsis. - Family Porellaceae,
Porella. - Family Goebeliellaceae,
Goebeliella. - Family Radulaceae,
Radula. - Family Frullaniceae,
Frullania. - Family Lejeuneaceae, 18 genera, originally subgenera of
Lejeunea, keyed separately.
-
Sub-order 3 Metzgerineae (Jungermanniales anacrogynae)
- Family Treubiaceae,
Treubia. - Family Fossombroniaceae,
Fossombronia Petalophyllum. - Family Pelliaceae,
Calycularia, Allisonia. - Family Pallavicineaceae,
Pallavicinia, Symphyogyna, Hymenophytum. - Family Metzgericeae,
Metzgeria. - Family Riccardiaceae,
Riccardia. - Family Monocleaceae,
Monoclea.
Marchantiales
Thalloid, vegetative body consisting of epidermis, an upper zone of green tissue with or without air-chamber (with pores) and a lower
- Family Marchantiaceae,
Marchantia, Lunularia. - Family Rebouliaceae,
Reboulia, Asterella, Plagiochasma. - Family Targioniaceae,
Targionia. - Family Ricciaceae,
Ricciocarpus, Riccia.
Anthocerotales
Thalloid, with smooth rhizoids, no ventral scales. Cells usually with one large chloroplast. Sporogonium with a bulbous foot, a sheath, and a long sessile capsule, bursting from the top downwards into two valves, columella generally present. Antheridia sunk in the upper surface of the thallus, ultimately bursting free.
Family Anthocerotaceae, Anthoceros, Aspiromitus (on the authority of Pearson), Megaceros, Dendroceros.
Key to Genera
Legends to Figures
Plate 1
1. Diplasiolejeunea lyratifolia ventral, showing duplicated stipules, one for each leaf, × 10.
2. Diplcphyllum domesticum dorsal, showing small dorsal leaf-lobes, × 5.
3. Strepsilejeunea Curnowii ventral, showing acute, decurved leaf-apices, × 10.
4. Bazzania Novae-Zelandiae ventral, showing incubous leaves and ventral axillary branching, × 4.
5. Bazzania Novae-Zelandiae dorsal, showing incubous leaves, × 4.
6. Balantiopsis diplophyllum dorsal, showing terminal marsupium, × 6.
7. Chiloscyphus ammophilus dorsal, showing succubous leaves, × 5.
8. Lepidozia tetradactyla dorsal, showing deeply divided leaves and lateral perianth, × 8.
9. Radula Levieri ventral, showing lobules, absence of stipules and spent capsule, × 10.
10. Lophocolea subporosa dorsal, showing terminal perinath with 3rd keel dorsal, × 5.
11. Cephaloziela sp., dorsal, showing deeply pluri-plicate perianth and bi-fid leaves, × 12.
12. Goebeliella cornigera ventral, showing double lobules and entire stiples, × 10
13. Elaters, A Metzgeria violacea monospiral, × 125; B. Frullania rostallata monospiral; C. Radula Levieri bispiral.
14. Pseudolates of Anthoceros × 100.
15. Cells of Lejeunea sp. without trigones, ca. 40 microns.
16. Rhizoids; D. Reboulia hemispherica, smooth; E. Lunularia cruciata, tuberculate, × 125.
17. Asterella australis × 16, F carpocephalum showing laciniate perianth, × 4.
18. Targionia hypophylla with terminal valves, × 1½.
19. Riccardia marginata showing absence of nerve and lateral calyptra, × 3.
20. Anthocercs with linear dehiscing capsule, nat. size.
21. Marchantia with male carpocephalum and rounded gammae cups; G. female carpocephalum showing involucres between the rays, nat. size.
22. Metzgeria furcata dorsal with ventral calyptras showing, also mid-rib and ciliate margins; H. ventral with male branches, x. 4.
23. Reboulia hemisphaerica, carpocephalum, underneath view showing bi-valved involucres, × 2½.
24. Plagiochosma australe with invol. lobes opening vertically, × 2½.
26. Lunularia cruciata with lunate gemmae cups, nat. size.
27. Sypmhyogyna hymenophyllum showing involucral scales and calyptras; I. sterile archegonia adhering to calyptra, × 2.
28. Pallavicinia Lyellii, J. invol. cup, K. perianth with calyptra included, nat. size.
29. Hymenophytum phyllanthus, L. basal ventral invol. cup, M. perianth, calyptra included, nat. size.
30. Dehisecnt capsules; N. Taxilejeunea Colensoana showing valves not divided to the base, × 10; O. Plagiochila × 7; P. Fossombronia × 7; Q. Metzgeria furcata with elaterophones × 10; R. Asterella × 5.
Lejeuneaceae
The ever-increasing genera of this family are in some cases imperfectly understood and hard to separate. It is doubtful if both Drepanolejeunea and Harpalejeunea are present in New Zealand, as recorded by Stephani. Physocolea and Leptocolea were originally divisions of Spruce's sub-genus Cololejeunea. These two divisions are now treated as genera, but the original name of “Colojeunea” has been substituted for that of “Physocolea,” as used by Stephani, and Herzog. In Descriptions of New Species of N.Z. Hepatics, Trans. Roy. Soc. N.Z., 1938, pp. 45-46.
Key To New Zealand Genera
A Glossary of Terms Used in This Paper.
Antheridium, the organ containing the male cells.Archegonium, a flask-shaped organ containing the embryo sporophyte, (Fig. 27).Axil, the angle between the stem and a leaf.Bifid, 2-cleft to half-way or thereabouts, (Fig. 11).Capsule, the sporangium or terminal portion of the sporophyte which actually contains the spores, (Figs. 9, 25).Carpocephalia. See receptacle.Calyptra, the inmost protective covering of the sporophyte, being the remains of the archegonium. Always present in the fructification, though sometimes fused with the perianth, (Fig. 19).Cauline, pertaining to the stem, used of leaves and stipules in contradistinction to those of the involucre.Chloroplast, a green body in plant cells.Ciliate, fringed with cilia or hair-like outgrowths, (Fig. 22).Columella, the central column in the capsule of the Anthocsrotaceae.Complicate, folded together.Cuspidate, terminating in a sharp rigid point cr cusp.Decurved, bent towards the ground or ventral aspect. (Fig. 3).Dehiscing, the opening of the capsule in different ways to let the spores escape, (Fig. 20).Dorsal, the front side of a leaf or stem, or that further from the ground or substratum, antical, (Fig. 2).Elaters, long and slender single or compound cells mixed with the spores, with spiral thickenings in their walls, (Fig. 13, A, B, C).Elaterophores, elaters, maybe of a different shape which remain fixed in a tuft at the base of the capsule inPelliaceae, or at the top of the valves inRiccardiaandMetzgeria, (Fig. 30, Q.).Emergent, used in speaking of a perianth which is partly concealed by the involucral leaves.Entire, stipules without an apical sinus inFrullaniaandLejeunea, or any margin without projections or incisions.Epidermis, the uppermost layer of cells of a thallus.Evanescent, of short duration.Falcate, sickle-shaped.Fimbriae, narrow processes.Flagelliferous, bearing longly attenuated branches.Foliose, with leaves, used of hepatics as opposed to the thalloid group.Globose, globular or spherical.Homomallous, descriptive of leaves all pointing in the same direction.Hyaline, glassy, transparent.Imbricate, overlapping like the tiles of a roof.Immersed, descriptive of a perianth that does not protrude beyond the involucral leaves.Incubous, when the leaf is so inserted that the dorsal margin overlaps the ventral of the leaf above it, (Figs. 4 and 5).Infra-Axillary, branches contiguous to the outer base of the leaves.Innovations, shoots which arise from below the perianth.Intra-Axillary, when the branches spring from the inside of the leaf-axil.Involucre, the outermost protective covering of the sporophyte, in the thalloid hepertics a ring or cylinder of tissue, or scales; in the foliose, consisting of enlarged leaves, (Figs. 21, 23).Lacerate, jagged or torn.Lobule, when the ventral lobe of a leaf is smaller than the dorsal, it is spoken of as the lobule, (Fig. 9).Marsupium, a fleshy sack enveloping the sporophyte, serving the purpose of a perianth, (Fig. 6).Median, belonging to the middle of a thallus, leaf, etc.Multistratose, when cells are arranged in several layers.Obovate, inversely ovate, attached by the smaller end.Papillae, minute processes arising from the cuticle of the cells.Papillose, bearing papillae.Perianth, the envelope surrounding the calyptra, (Fig. 8), strictly speaking, formed of united leaves. In the thalloid hepatics often known as the pseudoperianth.Plicate, with longitudinal folds.Pluriplicate, with many folds or plicae, (Fig. 11).Protonema, a simple structure from which the sexual generation is formed.Pseudoelaters, a row of irregularly shaped sterile cells, often geniculate, without spiral bands, found in the capsules ofAnthoceros, (Fig. 14).Receptacle, an elevated and expanded portion of the thallus modified to bear the sexual organs, = carpocephalum.Rhiziferous, bearing rhizoids.Rhizoids, long hairlike outgrowths, resembling rootlets, (Fig. 15).Seta, the stalk of the capsule.Sinus, the notch, acute to lunate, between two points.Sporophyte, the asexual generation consisting of the capsule (sporangium), its seta and base, sometimes called the sporogonium.Squarrose, set at right angles to the stem.Stipules, the third or ventral row of leaves sometimes called amphigastria or underleaves, (Fig. 1).Stomata, openings through the epidermis of the capsule inAnthocerotaceae, bounded by 2 guard-cells.Succubous, when the leaf-base is so inserted that the dorsal margin of the leaf overlaps the ventral margin of the leaf below it, (Fig. 7).Terminal, proceeding from the apical cell of stem or thallus, (Fig. 10).Thalloid, consisting of or resembling a thallus, frondose.Thallus, a flat vegetative structure not differentiated into stem and leaves.Transverse, when the leaf insertion is straight across the stem.Trigones, thickenings of the walls where 3 or more cells meet, (Fig. 15).Trigonous, 3-angled.Unistratose, arrangement of cells in one layer.Undulate, wavy.Ventral, the back side of leaf or stem, or that facing the ground or substratum.
, Zoology Department, Victoria University College.W. H. Dawbin
Holothurians or sea cucumbers form a class whose members are strikingly different from those of the other classes of Echinoderms. They have been distinct for a great length of time, as clearly recognisable holothurians (Eothuria) are known from the Upper Ordovician of Girvan, Scotland. These very ancient specimens show more features in common with the Echinoidea than are shown by any recent holothurians and in particular have a test of loosely fitting plates, even in the adult. In recent forms there is a reduction of the calcareous test to the form of small bodies of varied shape embedded in the body wall and not imposing the rigidity of structure so characteristic of the other Echinoderms. As a consequence holothurians are soft bodied, many being worm-like and unattractive in appearance and the group is less frequently noted or gathered by collectors than are the other Echinoderms. Only one species, the rather conspicuous, mottled brown Stichopus mollis, found below the low tide level in Cook Strait and Stewart Island is commonly recognised in New Zealand as a sea cucumber and it is just as frequently referred to as a “sea-slug.”
Representatives of the class are, however, known from a variety of habitats on the sea floor, ranging from the intertidal zone to the greatest depths from which dredgings have been obtained. In and a little below the intertidal zone in tropical waters, especially in coral reefs, holothurians are often large, or vividly coloured and comprise a conspicuous part of the fauna. Some of the larger species are important as beche-de-mer or trepang, whose sun dried bodies form an important item of food for a number of Oriental peoples. Most of the abyssal holothurians belong to the order Elasipoda which is not known from shallower water and so cannot strictly be included in the fauna of New Zealand. One small group, the Pelagothuriidae, are the only holothurians in which the adult is adapted for swimming, but so far no Pelagothuria has been taken in New Zealand waters.
Most of the New Zealand species are rather small and inconspicuous or live buried in sand and mud, and can only be found by careful searching, while many are as yet only known from deeper water. Some of the latter have been thrown up on beaches, occasionally in enormous numbers after heavy storms and have become known in this way, while others have only been collected by dredging in deeper water. From all these habitats the total number of holothurians described for New Zealand (including the Auckland and Campbell islands) is twenty-nine, and a distinctive variety of one of these species has also been described. All these species are included in the present key. Other species may possibly be found by careful searching in the intertidal zone, and it is
Our present knowledge of the New Zealand species began with the description of eight species by Hutton in 1872 and three more in 1878, but he did not describe calcareous deposits in either of these papers. The main foundation for the knowledge of New Zealand holothurians was laid with more detailed accounts by Dendy (1896) and Dendy and Hindle (1907). A number of smaller papers by other authors have appeared and are cited by Mortensen (1925) who made a careful revision of nearly all the previously known species and added ten new ones from the material collected during his stay in New Zealand in 1915. This brought the New Zealand total to its present number.
The identification of holothurians by external features is made difficult by their tendency to contract strongly, and to withdraw tentacles and tube feet on preservation. In this state it is very difficult to gauge accurately the size of the living animal and many species then appear very similar externally, although it is usually possible to determine the main group to which they belong. The difficulty can be partially overcome by narcotising the animal in sea water to which Epsom salts is added. In this they usually extend and when completely narcotised they should be preserved in alcohol. Lengths given in this key are for specimens extended in this way. For the more precise identification of holothurians it is usually necessary to examine the shape and relative numbers of the small calcareous particles in the body wall. This can be done by treating a piece of the body wall with a solution of bleaching powder (sodium hypochlorite) and then examining it under a microscope. By this means it is also possible to see the arrangement of the calcareous particles. If the body wall is thick, the particles can be separated out by gently boiling a small piece in a 5 per cent, solution of caustic potash, until the softer portions are macerated away, leaving only the calcareous particles. These may vary in shape even within a single individual, and changes during the life of the animal are known in some species. In spite of this there is sufficient distinctiveness between the species in the shapes, sizes and arrangements of these particles to make them the most important of the diagnostic characters for identifying holothurians. Identifications arrived at by other means should, if possible, be checked against a detailed account of the spiculation of that species. Excellent descriptions of a number of species and references to papers decribing the remainder are given by Mortensen (1925) Vid. Medd. Dansk. naturh. For., 79, p322 et.seq. Name changes introduced by H. L. Clark since Mortensen's account are Mensamaria bicolumnata (formerly Pseudocucumis bicolumnatus), M. thomsoni (formerly P. thomsoni) and Lipotrapeza dearmatus (formerly Phyllophorus dearmatus).
The locality records given in this key are for points from which the species has definitely been collected and are not meant to imply that the species is confined to those localities. Further collecting will doubtless show that a number of species are considerably more widespread than is known at present.
Explanation of Plates.
Plate 1.
These figures are not drawn to the same scale; sizes are given in the key. Fig. 1. Anterior end of Stichopus mollis showing ventral side bearing tube feet, and the tentacles with disc shaped tips (T) surrounding the slit like mouth. Fig. 2. Psolus neozelanicus, dorsal side showing imbricating scales. Fig. 3. Psclidiella nigra, latero-ventral view showing distinct light coloured sole bearing tube feet round the edge and a double row along the centre. Fig. 4. Cucumaria ocnoides, side view showing tube feet restricted to three rows (two showing) in the middle third of the body. Fig. 5. Paracaudina coriacea. Fig. 6. Profuse branching found in the tentacles of Order Dendrochirota. In preserved material the branching may appear to be much more crowded than illustrated. Fig. 7. Finger like processes of tentacle typical of many of the Order Apoda. Fig. 8. Trochodota dendyi.
Plate 2.
Fig. 9. Cucumaria bollonsi, buttons and cups from the skin. Fig. 10. C. brevidentis, a button. Fig 11. C. calcarea, a button. Fig. 12. C. farquhari, A. part of large scale; B. cup. Fig 13. C. amokurae, A. large scale from side of the body; B. × shaped bodies. Fig. 14. Mensamaria bicolumnata, tables bearing a double spire. Fig. 15. Phyllophorus longidentis, plates bearing a double spine. Fig. 16. Paracaudina coriacea, a rounded plate. Fig. 17. Molpadia marenzelleri. A. anchor plate; B. anchor; C. perforated plate bearing spine; D. phosphatic concretion. Fig 18. Wheel as found in many of the Order Apoda. Fig. 19. Hook or sigmoid body as found in Trochodota. Fig. 20. Protankyra uncinata, A. anchor; B. tentacle bearing two pairs of finger like processes, and sensory cups on the stalk. Fig. 11. Chirodota nigra, smooth oval bodies found along the muscle radii. Fig. 22. Chirodota gigas, thick curved rods from along the radii. (Figs. 2, 9, 12, 13, 20, after Mortensen; figs. 14, 22, after Dendy and Hindle; fig. 17 after Theel.)
Additional Species
A key to the sea urchins was published in Tuatara, 1 (3) 1948. Since its publication the following new species have been added to the faunal list. The original key may be brought up to date if the addenda below are made.
New sub-paragraph, to be added under 5 (page 7):—
After the diagnosis for Evechinus chloroticus, insert:—
Delete paragraph 10 (page 8), and insert the following in its place:—
Rec. Auck. Mus.,3 (6), pp. 343-346, 1949.
Unfortunatley a slip was made in keying the mosses with 3 rows of leaves: Rhacopilum is the only genus with a dorsal row of leaves, not Cyathophorum as shown.
Numbers 11-14 of the key should read as follows: