460 Anali/tical Notices of Books. 



sibility of doubt the proof of the identity of Nyctinomus with 

 Molossus, The type of the former genus, the Nyct. j^gyptiaciis^ 

 Geoff., possesses in its early age the four incisor teeth which have 

 been made to characterize the group, but loses two of them, when 

 arrived at its full growth, and thus becomes an undisputed Mo- 

 lossus. 



On the importance of these remarks we need not observe. The 

 anomalies which exist in the dentary system of the Cheiroptera 

 have long been a stumbling-block to Zoologists, and can only be 

 explained by a continued and extensive series of minute examina- 

 tions, similar to those to which M. Temminck has subjected them. 

 They afford an additional proof, if such were wanting, that a sys- 

 tem founded on any one set of organs, however important, must 

 become in some of its parts deficient and inadequate : it must 

 degenerate into a merely artificial method, the natural one being 

 attainable only by a well-directed study of the whole organisation. 



The species of Dysopes are enumerated in the following order ; 

 the primary sections, to which no characters can be assigned, 

 being derived from their habitation in the two great divisions of 

 the globe. 



* Species which inhabit the Old World. 



1. Dys. cheiropus. This is identical with the Cheiromeles tor- 

 quatus^ Horsf., and is established on the single specimen which 

 exists in the collection of the East India Company, and was des- 

 cribed and figured in the Zoological Researches in Java. No 

 other individual of the species has yet occurred. The description 

 given by M. Temminck was prepared before he was acquainted 

 with that of Dr. Horsfield ; his figure is copied from the one pub- 

 lished in the work of our able co-operator. M. Temminck does 

 not agree with him in regarding it as the type of a distinct genus. 

 The only character, he remarks, that separates it from the JSycti" 

 nomi is the opposable nature of the external toe of the hinder feet. 

 An analogous structure, though less in degree, is, in his opinion, 

 possessed by other species of Dysopes ; the Dys. velox has the 

 same toe stronger than the others, free, and articulated laterally ; 

 in the Dys. Ruppelii, it is free, but is not capable of opposition to 

 th« others, nor is it furnished with a broad, depressed uail ; and 



