1878.] 



CLASSIFICATION OF THE CERVID.E. 



897 



(15) The antlers of the Cer- 

 vidse are subject to great varia- 

 tion ; and such variations are 

 transmissible by heredity. 



(16) Two species have a cir- 

 cumpolar range, and Cervus 

 canadensis, a species allied to the 

 common Red Deer of Europe, is 

 found in North America. 



Facts (continued). Hypothesis (continued). 



attributed to the same cause. 

 (14) There are only twenty- (14) The Deer of South Ame- 

 two species in America ; and the rica, which, according to the 

 South-American species have theory under consideration, have 

 remarkably simple antlers. been freer from contact with al- 



lied forms than species inhabit- 

 ing districts nearer to, and more 

 in direct continuity with, the 

 centre of the family area of dis- 

 tribution, are remarkable for the 

 great simplicity of their antlers. 

 (15, 16) For long periods there 

 was no possibility of communi- 

 cation between the Deer of the 

 Old and New World ; and during 

 this time the perpetuations by 

 heredity of the more favourable 

 varieties which arose from time 

 to time resulted in the diver- 

 gence of the Cervidae into the 

 clusters of species which we now 

 term genera. (16) At length 

 the means of dispersal was for a 

 second time opened between 

 Asia and North America ; an 

 interchange of species took place ; 

 the ancestors of Cervus canaden- 

 sis passed over into North Ame- 

 rica from the Old World, and the 

 Elk and Reindeer extended their 

 range till it was circumpolar. 



In the following synopsis I have admitted every species of whose 

 invalidity I am not absolutely certain ; and frequently, even where I 

 have felt grave doubts as to the soundness of the claims of a species 

 to specific recognition, I have left it distinct, if by so doing I have 

 thought it probable that future investigation of its claims may throw 

 light on the important problems of geographical variation and dis- 

 tribution. Where colour is not mentioned in the diagnoses it affords 

 no generic or subgeneric character. Supplementary columns are 

 absent in the molars, and the central incisors are much expanded, 

 where the contrary is not stated. Where the metatarsal and tarsal 

 tufts are not specially mentioned, they are present. 



V. Synopsis of the existing Cervidae. 

 A. Proximal ends of lateral metacarpals remaining. 



(Plesiometacarpi.) 

 Posterior portion of the nasal cavity not divided by the vomer 

 into two distinct chambers. 



