i892. 



SOME NEW BOOKS. 627 



events, of these deficiencies that M. Coupin has prepared the treatise 

 mentioned above. The work is intended for students preparing for 

 examination, and from this standpoint it must, in fairness, be judged. 

 We may say at once, then, that, though not perfect, it is much 

 superior to the majority of works compiled with such an object in 

 view. 



Each class of the Mollusca is considered separately, and all 

 generalisations referring to the group as a whole are deferred to the 

 end of the work ; a mode of treatment which has many advantages 

 over the more usual plan of giving generalities first and details after- 

 wards. As regards classification, we find six classes adopted : — 

 Acephales, Scaphopodes, A mphineitres, Gastcvopodes, Pteropodes, Ccphalopodes. 

 No objection of weight can be urged against the use of Acephala for 

 the first of these, though it is, perhaps, more suitable as applied to a 

 dichotomous division of the Mollusca, and contrasted with Cephalophora 

 or Glossophova. In his discussion of this group, the author departs 

 from his usual practice of selecting a concrete example for descrip- 

 tion, giving only an account of an ideal type, with certain comparative 

 observations. This seems to us an error of judgment ; the study of 

 an actual form impresses upon the mind of the student a quantity of 

 definite information, and comparisons can be just as well instituted 

 with a tangible example as with an ideal type. 



With this exception, the treatment of the Acephala may be taken 

 as representing that adopted in the case of the other classes, and 

 it is on the whole satisfactory. The different systems of organs are 

 taken up seriatim, beginning with the shell, mantle, muscles, and so 

 forth. The descriptions are clear and concise, and are profusely 

 illustrated by cuts, some copied from well-known works, but the 

 greater number evidently, as stated by the author in his preface, 

 reproductions of lecture diagrams. Many are rather rough, but they 

 are clear, and a great help in the elucidation of the text. The work is 

 well up to date, and in many cases references are given to original 

 sources of information, though not so frequently as might be desirable. 

 Following upon the anatomy are a few pages treating of embryology, 

 then comes a resume in half-a-dozen lines of the main characters of the 

 group, and finally a systematic view of its principal families, with 

 occasional mention of conspicuous genera. Some of these notes are 

 good and to the point, but others are too brief to be of any use ; as for 

 instance, under "9° Mactridis" the only information vouchsafed is 

 " Les Mactra ont une coquille ventrue." Precisely the same character 

 is emphasised in the case of the Arcadce. 



It seems needless to follow the author in detail through his treat- 

 ment of the remaining groups. We cannot, ho\vever, conceal our 

 astonishment that he should retain the Pteropoda as a distinct class, 

 when he is evidently well acquainted with the work of Pelseneer and 

 others on this question, and, by his own admission (p. 191), attaches 

 great weight to their arguments. 



The descriptions are in the main accurate, though errors in 

 matters of detail occur here and there, as, for instance, when the 

 figure of a tentacular club of Sepia tuherculata is made to do duty for 

 that of 5. officinalis, and no mention is made of the infrabuccal cushion 

 on which the female Sepia receives the spermatophores. Taken all in 

 all, however, the book is probably the best small text-book extant of 

 malacology as opposed to conchology. It is much to be regretted that 

 its pages are disfigured by a plentiful crop of misprints. 



W. E. H. 



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