Cope.] ^'^O [Oct. 7- 



the usual pair. Bos develops complications of the molar teetb in both 

 jaws. 



On the brachyodont side the development of the dermal covering of 

 the horns of Blastomeryx is arrested, and naked horned types follow. In 

 the Sivatberiine grouj) no further change follows except complication of 

 the horns. In the Cervine group, on the contrar}^ the habit of shedding 

 them becomes fixed, and a new family has its origin.* 



Of the Cervid^ or the Booidea which shed their horns, the genus Cervus 

 is one of the earliest with which we are acquainted. Undoubted speciea 

 of the genus occur in the Pliocene, and Upper Miocene species are also 

 referred to it. As species from the Lower Pliocene (C matJieroni Gerv.) 

 are referred to Capreolus, those of the Miocene may not be true Cervi. 

 Their structure is not sufficiently known to determine this point. The 

 arrangement of the genera is as follows. The three primary divisions 

 were established by Brooke. 



I. Lateral metapodials complete only distally, and supporting deer 



claws (Telemetacarpi). 

 a. Nasal passages posteriorly two, separated by vomer (Cariaci) 



Horns simple spikes Coassus Gray. 



Horns more or less furcate Gariacus Gray, 



Horns palmate Bangifer H. Smith 



aa. Nasal passage posteriorly one, not divided (Oapreoli). 



No horns Hydropotes Swinh. 



Horns furcate ; no postantler Capreolus Gray. 



Horns palmate ; no postantler Alces H. Smith. 



Horns palmate ; a postantler Gervalces Scott. 



II. Lateral metapodials represented by proximal splints only ; nasal 



passage not divided (Plesiometacarpi). (Cervi.) 



Frontal cutaneous glands ; horns furcate Cervulus Blv. 



No frontal glands ; horns simple Elaphodus M. Edw 



No frontal glands ; horns furcate Gervus Linn. 



No frontal glands ; horns palmate Dama H. Smith. 



Horns furcate ; brow antler greatlj'^ exceeding beam, (Gill) 



Elapliunis M. Edw. 



The phylogeny of these genera cannot be fully known until the skele- 

 tons of the extinct genera and species have been obtained. It is, however, 

 certain that the short series of genera included in each of the three 

 divisions (II a and «a, and HI), are genetic series ; and also that division 

 I is ancestral to both II and III, although perhaps by an extinct genus 

 differing in some respects from Moschus. These relations can be thus 

 expressed : 



* I have described the probable mode of origin of the deciduous horns of the deer in 

 Eeport U. S. G. Survey, W. of 100th Merid., iv, p. 348, 1877. 



