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REVIEW R. C. MOORE,(Director and Editor), Treatise on Paleontology, Part R, Arthropoda, 4: 1-651, 3 tables and 397 figures. (University of Kansas and Geological Society of America Inc., Boulder,- - - - Colorado,-- - . - - , -1969). , - , , . These two volumes fill out the Arthropoda section of this Series, an endeavour which began with Part P in 1955 and which will not be completed until the large third volume of Part R (fossil Insecta) appears. Only the introductory and entomostracan chapters (pp. Rl-295, p. R628) are reviewed here. Like all the Treatise volumes these are impressively produced. They are set in a clear , use the proven Treatise format and are well illustrated. The larger volume carries a valuable glossary but, with the notable exception of the chapter on Cirripedia, lacks the useful tables which in previous volumes have afforded non-specialists handy primers on generic time-ranges. In his Introduction, Moore notes that Part R has been more difficult to organise than any previously published Part. It might have been hoped that, as a result of this long gestation, Part R would date less rapidly than some other volumes in the Series. Certainly, it gets off to a notable start with the synthesis by Manton of her ideas on the and relationships of living arthropods which have developed as a result of detailed work on arthropodan functional anatomy and habits of . Since Manton's papers are sometimes difficult to read, because of the wealth of detail which needs to be assimilated by the reader and which bears on her conclusions, all workers will be very grateful that such a precis is now available. Manton shows clearly the separateness of the from the trilobitan-cheliceratan and onychophoran-myriapodan-hexapodanlines and stresses the outstanding convergencesand examples of parallel evolution which must be faced in setting up a natural classification for Arthropoda, concluding in favour of, "...Some measure of polyphyletic evolution within the group...". Few practitioners would quarrel with this diagnosis which here is backed up by a more detailed exposition with clear illustrative figures in the early part of her second chapter. Some possible corollaries, however, may not be as palatable. For example, there is no evidence other than super- ficial similarity to link with the strange Cambrian from AYJheaia. On the other hand, as Manton shows (pp. R39-41), the relationships among living arthropods suggest affinities between Onychophora and the Myriapoda. As the fossil record of myriapods begins in the Devonian perhaps it was at this time that Onychophora evolved, in a form superficially convergent with that of Ay.rheaia.There seem to be no compelling reasons why the group should greatly antedate either other myriapods or the new habitat opportunities provided by the earliest widespread land vegetation. In a significant paragraph, Manton redefines the concept of grades in evolution as showing, "... levels of organisations reached independently by various classes..." (p. Rll). Among other examples of this she includes the development of mandibles- it was criticism of the concept of the subphylum Mandibulata which led to the invitation from Moore to participate in the Treatise. The closing pages of her contribution form a concise marshalling of the state of knowledge to 1966 and in general develop reasonable interpretations therefrom. Crustacean neontologists may note a few factual errors or omissions, such as the statement that no primitive Ostracoda, Cirripedia or Branchiura are alive to-day (p. R52). It is a fact that at least one family and most modern orders of Ostracoda, for example, are known unequivocallyto have persisted since the Ordovician. Parenthetically, one wonders how much longer crustacean phylo- geneticists will continue to disregard the Ostracoda, a group including numerous taxa with some primitive characters in any sense of the word and with the most abundant and longest continuous fossil record in the phylum. Further, Manton's statement, "... Whether Ay.rheaiawas -living or littoral is uncertain .. ," is factually elastic if it is intended to imply that the marine environment for this form is in question. Diverse evidence suggests in site preservation of the Burgess Shale fauna (which includes Ay.rheaia) in a calm, poorly oxygenated,sublittoral marine environment. It is a fact that in such an environment living Onychophora would quickly drown (Manton, 1938). Although her work is not time-oriented, Part R indicates that Manton's conclusions regarding Pauropoda, the diplopod Siphonophora, Symphyla and Scutigera in the main are supported by the objective test which the existing fossil record affords them. 111

Manton's conceptual framework is followed by a brief chapter on the general features of Crustacea which incorporates the glossary referred to earlier and ends with an outline of the classification of Crustacea which is used in these volumes. The authors, Moore & McCormick, have drawn on specialist knowledge in their compilation but one can still remark critically that the number of Recent ostraGodegenera is nearer 500 than 100 and that there are at least 1000 described Recent freshwater ostracode alone apart from the hordes of marine taxa. The first of the systematic chapters, that on Cephalocarida, follows. A generally clear and well illustrated documentation is marred by subjectivity in the later paragraphs on evolutionary signifi- cance. For instance, the statement that it is possible to derive the limbs of all classes of from a cephalocarid type has little meaning at the purely morphologic level at which it was investigated (see also p. R51) since a similar claim could be put forward for other groups - after all the crustacean limb-type is highly adaptable. Further, the evidence from head appendages may equally be taken to imply that at least calanoid Copepoda, Mystacocarida and cladocopan Ostracoda have a longer evolutionary history than cephalocarids. Similarly, different interpretations can be made regarding some cephalocarid musculature (McKenzie, in press). A minor point of taxonomic criticism is that the Japanese taxon, Sander.riella,has not been picked up in an Addendum although Hessler (p. R127) is evidently aware of its existence (Shiino, 1965). Tasch's chapter on the Branchiopoda in part complements his paper in the "Phylogeny and Evolution of Crustacea" (Tasch, 1963) in that he here formalises the classification then championed by Brooks and himself. Tasch prefaces the systematicsof each main group - notostracans, concho- stracans, cladocerans and anostracans - with informative notes on their anatomy, development and ecology and includes suggestions on the kinds of palaeoenvironmentsin which their preservation would be favoured. In the Conchostracasection, a nearly full systematictreatment writes off a large number of Novozhilov's Russian genera, especially among the cyzicids,as, "Inadequately documented; doubtful". One of these, Konlikia, is doubtful indeed since it is a junior of Paleolimnadia Raymond (assigned to a different family) which has the same type species, Estheria wianamat'taensis Mitchell, from the Triassic of New South Wales, Australia. The Recent family Imnadiidae is not listed (Botnariuc, 1947). Cladoceran specialists will note the omission of the handsome large Australian , Saycia Sars, as well as about 20 other genera of Cladocera, including (in the systematic section) two families, Holopediidae and Macrothricidae,both with fossil records (Frey, 1964, 1967). A minor point is that Peracantha is misspelt on four of the five occasions on which it appears. Although too recent to have been incorporated into the Treatise, Fryer's major paper on the functional of chydorid cladocerans is worth mentioning here for the students who will use Part R because it breaks new ground in the study of the group and is supplementaryto Manton's work (Fryer, 1968). Also, Adamczak's work on Cambrian phosphatocopine cladoceran-like forms has become more detailed since his 1961 paper and was worth some further comment, even though it is probable in my opinion that these early forms are examples of convergence(Adamczak, 1965). Taxonomists looking for systematic completeness in the Anostraca section will be disappointed and are referred especially to the work of Brtek (1964, 1965, 1966) which could have been picked up for the Treatise via an Addendum. Significant new ecological and physiological work includes that by Broch (1965) and Moore (1955 et seq.). Four short chapters, on Mystacocarida (Hessler), Euthycarcinoidea(Moore), Copepoda (Palmer) and Branchiura (Hessler), follow. Of these, the chapter on Copepoda is much too short since they are a major group exhibiting a remarkable diversity of to humid terrestrial and aquatic land and marine environments. Also, they may yet develop some palaeolimnologicand archaeologic potential (Frey, 1964). The remaining chapter on entomostracans,that by Newman, Zullo & Withers on the Cirripedia, is in many respects the best. There is a full systematic treatment updated in an Addendum (p. R628), two useful tables - on generic time ranges and inferred phylogeny of the orders and families -, a long phylogenetic discussion and much detail on the morphology of Thoracica. But there is very little ecology and a consequent neglect of experimental work in this field especially by Barnes (e.g., Barnes, 1953, 1965). Anderson's recent paper on cirriped embryology (Manton, personal communication;Anderson, 1969) should interest those involved with the phylogeny of this ancient group. In summary, this is a valuable and necessary reference work which is highlighted by Manton's introduction and, in all the longer chapters, by numerous well reproduced figures. As few authors