lvon] 



THE HARES AND THEIR ALLIES 



379 



In some of the skeletons (and probably in all had they been care- 

 fully cleaned), in the angle between the unciform and the fifth meta- 





/^tc^ 



Fig. 45. — Carpus of the LeporidcE and Ocbotonidcr. i. Dorsal view of right 

 carpus of Sylvilagus floridaniis mallunts, No. 16,248, Carlisle, Pennsylvania, enlarged 

 nearly twice. 2. Proximal view of proximal row of carpal bones of same. 3. 

 Proximal view of distal row of carpal bones of same. 4. Dorsal view of right 

 carpus of Ochotona saxatilis, No. 49,620, Oregon, enlarged nearly four times. 5. 

 Proximal view of proximal row of carpal bones of same. 6. Proximal view of 

 •distal row of carpal bones of same, ac, accessory ossicle ; c, os centrale ; cii, 

 cuneiform ; inc-^, first metacarpal ; wic^, fifth metacarpal ; nig, os magnum ; ps, pisi- 

 form ; SC, scaphoid; sni, semilunar; t, trapezium; td, trapezoid; n, unciform. 



carpal, is a small bone which Forsyth Alajor calls the carpale 5. He 

 regards the unciform as carpale 4 only, instead of the fused carpalia 

 4 and 5. This small bone is otherwise known as the os vesalianum. 



OCHOTONID.E 

 (Figure 45, 4-6) 

 The carpus of the Ochotonidse differs in several respects from the 

 carpus of the Leporidse. The pisiform has less dorso-palmar depth ; 

 the lunare is narrower; the internal half of the cuneiform is more 

 largely developed, making up for the narrower lunare, and presents a 

 well-developed convex facet for articulating with the ulna, in addi- 

 tion to the cup-shaped cavity formed by the cuneiform and pisiform 

 jointly. The centrale is much larger than it is in the Leporidse, and 

 is not flask-shaped. The os magnum is reduced in size. A small os 

 vesalianum is present. 



