314 



F. B. Loomis — Osteology and Affinities 



Fig. 19. 



each with a high, carina, which is, however, confined to the 

 plantar side. 



The two first phalanges are long and slender, with the distal 

 ends expanded in true tylopod manner. The upper articular 

 surface is a shallow concavity, a notch 

 in the lower margin being the only 

 indication of the carina of the meta- 

 podial. The distal phalanges are a trifle 

 over half the length of the proximal 

 ones, and like them are considerably 

 expanded, though not to the extent 

 found in modern camels. The upper 

 articular face is a shallow groove, while 

 that on the lower end extends from on 

 the upper clear around on to the plantar 

 surface. The ungual phalanges are 

 high, long pointed, rounded on the outer 

 side and nearly vertical on the inner 

 face. They are typical for a distinctly 

 digitigrade artiodactyl. 

 The following figures give the measure- 

 ments for the various front limb bones in the three known 

 species : 



Fig. 19. Stenomy lus 

 hitchcocki, phalanges from 

 the upper side, x 1/2. , 





Scapula 



Humerus 



Ulnar-radius * 



Metacarpus 



Phalanges 





length 



width 



width 



of 

 fossa 



length 



diame- 

 ter of 

 head 



diame- 

 ter of 

 trochlea 



length 



thick- 

 ness 



10 5 

 13 



length 



thick- 

 ness 



length 

 12 3 



/S. hitchcocki 

 /S. crassipes 

 S. graeilis 



138 



78 



22 



168 

 194 

 195 



26 



32 

 37 



27'5 



28-57 

 33 



225(191) 

 229(194) 

 254(225) 



158-5 



166 



184 



11-25 

 13 5 



35 



41 

 44 



20 17 



Fig. 20. 



Fig. 20. Stenomylus hitchcocki, os innominatum seen from the lateral 

 aspect, x 1/2. 



Hind limb. — -While in general the innominate bone is of 

 the tylopod type, it is longer and relatively less expanded, 



* In parenthesis is given the length of the radius. 



