No. 3] OSTEOLOGY OF MESOH/PPUS AND LEPTOMERYX. 359 



In the dentition the characteristic points are : (10) the pecul- 

 iar spatulate form of the lower incisors; (u) the great simpli- 

 city of the premolars; (12) the presence of crests upon the 

 anterior crescents of the lower molars (this Schlosser regards 

 as the most important character of all) ; (13) the character of 

 the milk molars. 



In the vertebral column we observe : (14) the shape of the 

 atlas ; (15) the peg-like odontoid process of the axis ; (16) well- 

 developed neural spines on the cervical vertebrae; (17) the long, 

 curved, dorso-lumbar region. 



In the limbs we have : (18) the great length of the hind limbs 

 as compared with the fore limbs; (19) the ulna and radius are 

 not coalesced ; (20) the lunar rests almost entirely upon the 

 scaphoid; (21) the median metacarpals may coalesce into a 

 cannon-bone or not ; (22) the lateral metacarpals are complete ; 

 (23) the lower end of the fibula fuses with the tibia, except 

 sometimes in Dorcatherium ; (24) the cuboid, navicular, and 

 cuneiforms fuse into one compound bone ; (25) the median 

 metatarsals form a cannon-bone ; (26) the lateral metatarsals 

 are complete, though very slender ; (27) the keels on the distal 

 ends of the metapodials are confined to the palmar and plantar 

 side. 



It is obvious that Leptomeryx agrees with the tragulines as 

 regards much the greater number of these characters. The 

 skull is that of the chevrotains with most of the primitive feat- 

 ures emphasized. To this statement two exceptions must be 

 made : (1) the occiput is flattened or even concave, and (2) the 

 auditory bullae are small and not filled with cancellous tissue. 



In the dentition, we see that Leptomeryx agrees with the 

 tragulines in the characters 12 and 13, and differs from them 

 as to numbers 10 and 11. Some specimens, however, have pre- 

 molars as simple as those of Tragulus, which shows that this 

 character is not a constant one. We may add here that the 

 brain is also very traguline, but little weight can be given to 

 this fact, as there is the same resemblance between Moschus 

 and Tragulus. " In other respects, the brain of Tragulus, as 

 far as its surface markings are concerned, is a simplified miniat- 

 ure of that of the Cervid<z" (Flower, No. 17, p. 176). All 

 the traguline characters in the vertebral column recur in that 

 of Lepto?neryx. 



