July 3, 1896.] 



SCIENCE. 



25 



homholepis and Otomitla) is attained in the latest 

 members of the race with the least modified 

 exoskeleton or when he notes that at the time 

 the jaw elements become more simplified among 

 the Teleostomes, a ' new vigor ' is apparently 

 infused into their race, marked by the outcrop 

 of a varied series of families. By this means 

 parallelisms have been largely evaded, but of 

 these many interesting examples are cited, 

 as the structures arising in the Semionotids and 

 Ilacrosemiids, which are clearly interpretable as 

 the result of similar physiological needs. And 

 it was only after the closest sci'utiny that the 

 author was inclined to follow the lead of Prof. 

 Cope in selecting fin structures as the most con- 

 stant elements in comparison. The old tenets of 

 classification, the characters of scales and even 

 of vertebral axis, were found to be of decidedly 

 minor importance, in the, case of scales, as in 

 Eugnathus and Caturus of not more than generic 

 value. Throughout the volume phylogenetic 

 views are seldom expressed definitely, for even 

 the splendid series of forms which the author 

 has been able to study has not convinced him, 

 in the majority of cases, of more than probable 

 kinships ; thus we learn that the ' ' origin of the 

 ■Chondrostei is still entirely obscure, ' ' or that 

 ' ' it seems most reasonable in the present state 

 of knowledge to place the Oligopleuridse with 

 the (Pholidophoridse) near the base of the Iso- 

 spondylic Series," or, again, that, " if specula- 

 tion were permitted in seeking the direct ances. 

 tors of the Pycnodonts, it might be most profit- 

 able to turn toward the earliest Mesozoic fishes 

 of the CoZo&ocZits type. " 



Mr. Smith Woodward regards his volume as 

 acceptable ' merely as a convenient basis for 

 further research, full of imperfections which 

 each specialist will readily discover for him- 

 self.' But when one is familiar with the re- 

 searches of its author, and knows, moreover, 

 that the present volume embodies four years' 

 diligent work, we may naturally expect that its 

 sins, either of omission or commission, will not 

 prove formidable. If criticism must be found 

 ■one might be inclined to regret that the number 

 •of text figures, especially restorations, were not 

 larger, although be it understood that from the 

 obvious nature of the catalogue this number is 

 already a goodly one. Bashfoed Dean. 



The Cyprinodonts. By S. Garman. Memoirs 

 of the Museum of Comparative Zoology at 

 Harvard College. Vol. XIX., No. 1, pp. 

 179, pis. XII. 1895. 



The present monograph on the ' top min- 

 nows ' has been based upon Mr. Garman' s stud- 

 ies of the remarkable — possibly the most com- 

 plete — collection of these forms, that of the 

 Agassiz Museum at Harvard ; and it is certainly 

 one of the most valuable of recent contributions 

 to the study of Fishes. It is important to the 

 systematist, because there is scarcely a group of 

 recent Teleostomes which has stood in greater 

 need of critical revision, for the Cyprinodonts 

 are not merely a large and scattered group, pro- 

 fusely and often very imperfectly described, but 

 one whose species present a most confusing- 

 range in coloration, dentition and sexual char- 

 acters. 



One cannot help feeling that in the systematic 

 portion of the work Mr. Garman' s studies of 

 the variation among members of each species 

 have enabled him to interpret ' specific ' dififer- 

 ences with modern broadness, and that the or- 

 der which has been drawn out of the tangle of 

 synonymy (where a single form had, for exam- 

 ple, been placed by various authors in as many 

 as a half dozen 'genera') is one which will 

 prove of permanent value. The monograph 

 is one which, like that on the Discoboli, does 

 fitting justice to its author's careful work ; it 

 might well be taken as a model of thoughtful 

 preparation. The plates are admirable exam- 

 ples of the work of the artist and of the lithog- 

 rapher, and especially interesting are Pis. IX.- 

 XII. , which were drawn by Sonrel for the elder 

 Agassiz. 



The wide range in structural characters 

 which the Cyprinodonts have evolved has been 

 brought out clearly in the introductory portion 

 of the monograph, but perhaps not as fully 

 as many morphologists would desire. But the 

 arrangement of the material with a view of 

 sketching broadly the evolutional problems sug- 

 gested by this group is certainly satisfactory. 

 And there can be no doubt that many well- 

 trained morphologists will here learn, for the 

 first time, that sexual dimorphism — where the 

 males or females of the same species will be 

 either sinistral or dextral— may occur among 



