360 SCOTT. [Vol. V. 



In the fore limb there are no important differences between 

 Leptomeryx and the tragulines, even in matters of such detail as 

 the mutual relations of the carpal bones. In the hind limb, the 

 differences are more important. The lower end of the fibula 

 appears usually to remain free, though sometimes it fuses with 

 the tibia ; the cuneiforms do not coalesce with the cubo-navicular, 

 and only the proximal ends of the second and fifth metatarsals 

 are preserved, and they coalesce with the cannon-bone. But 

 even in the pes, the distal keels occur only on the plantar side 

 of the metatarsals. Thus in the twenty-seven characters enum- 

 erated above as distinguishing the tragulines, Leptomeryx agrees 

 with that group more or less completely in twenty-one. 



On the other hand, there are the following points of agree- 

 ment with the Pecora : (i) The character of the occiput ; (2) 

 of the auditory bulla ; (3) the form of the lower incisors ; (4) 

 the complexity of the premolars ; (5) the character of the tarsus, 

 and (6) of the metatarsus, except for the shape of the distal 

 end. If the more primitive extinct members of the Pecora 

 be included in the comparison, the number of correspondences 

 with Leptomeryx would be much increased. 



To those who accept the position of Boas, that the tragulines 

 are a group of simplified ruminants which have been derived 

 from typical members of that series, and not to be regarded as 

 a primitive group (No. 3, p. 522), the apparently intermediate 

 character of Leptomeryx would be just what we should expect, 

 and this genus would then be considered as one of the direct 

 ancestors of the tragulines. For reasons into which the limita- 

 tions of space forbid my entering here, I cannot agree with this 

 view, and therefore cannot adopt such an explanation of the 

 position of the genus before us. 



It seems clear to me that the probable interpretation of the 

 problem is this. Leptomeryx is a side branch of the traguline 

 stem, given off before the extreme concentration of the tarsus 

 characteristic of existing members of that stem had been 

 acquired, and which has paralleled more or less exactly the 

 characters of the Pecora in certain particulars ; e.g. the condi- 

 tion of the auditory bullae and the constitution of the posterior 

 cannon-bone. There is every reason to suppose that the char- 

 acter of the tarsus in Leptomeryx is nearly what it was in 

 the ancestral tragulines. Such a conclusion may seem highly 



