184 MAMMALIA, 



C. equinus. 13. C. marianus. 14. C. Peronii. 15. C. uni- 

 color. 16. C. Axis. 17. C. porcinus. 18. C. nudipalpebra. 

 19. C. Leschenaultii. 20. C. Capreolus. 21. C. Mexicanus. 

 22. C. paludosus. 23. C. campestris. c. Cerfs daguets. 24. 

 C. Nemorivagus. 25. C. rufus. This essay is a mere compila- 

 tion without any examination. 



M. Pucheran, in his " Monographic des especes du Genre 

 Cerf " (Comptes Eendus Acad. Sci. 1849, ii. 775), divides the 

 tribe Cerviens into four genera: 1. Alces. 2. Tarandus. 3. 

 Cervulus; and 4. Cervus. 



Since the publication of Cuvier's Essay on Deer (Ossemens 

 Fossiles, iv.), where he exhibited the development of the horns 

 of several species, and in which he described several species from 

 the study of the horns alone, many zoologists have almost entirely 

 depended on the horns for the character of the species ; and Mr. 

 Hamilton Smith has been induced to separate some species on 

 the study of a single horn. But the facilities which menageries 

 have afforded of studying these animals, and watching the va- 

 riations which the horns of the species present, have shown that 

 several most distinct but allied species, as the Stag of Canada 

 and India, have horns so similar, that it is impossible to distin- 

 guish them by their horns. On the other hand, it has shown 

 that animals of the same herd, or even family, and sometimes 

 even the same specimen, under different circumstances, in suc- 

 ceeding years have produced horns so unlike one another in size 

 and form, that they might have been considered, if their history 

 was not known, as horns of very different species. These obser- 

 vations, and the examination of the different cargoes of foreign 

 horn which are imported for the uses of the cutler, each cargo 

 of which is generally collected in a single locality, and therefore 

 would most probably belong to a single species peculiar to the 

 district, have proved to me that the horns afford a much better 

 character to separate the species into groups than to distinguish 

 the allied species from one another. 



Colonel Hamilton Smith, in his Monograph of the Genus, se- 

 parated them into genera according to the form of the horns. 



In the Proceedings of the Zoological Society for 1836 I drew 

 attention to the glands on the hind-legs, as affording very good 

 character to arrange the genera proposed by Colonel Smith into 

 natural groups, which in most particulars agreed with the geo- 

 graphical distribution of the species. 



Dr. Sundevall, in his Essay on Pecora, has availed himself of 

 the characters suggested in my paper, and has also pointed out 

 some other external characters, such as the form and extent of 

 the muffle, which afford good characters for the distinction of 

 these animals, characters which, I firmly believe, are much more 



