472 



LAND MAMMALS IN THE WESTERN HEMISPHERE 



heavy, but with no such relative bulk as in the Pampean genus. 

 The hump at the shoulders, as indicated by the spines of the 

 anterior dorsal vertebrae, though already well defined, was less 

 prominent. The shoulder-blade (scapula) was relatively 

 broader than in ^Toxodon, its spine had a distinct acromion 

 and two very long and conspicuous processes given off backward 

 from the spine, only one of which, and that a mere vestige, 



is indicated in ^Toxodon. The 

 hip-bones were almost parallel 

 with the backbone and were 

 not nearly so broad or so 

 everted as in the latter, a differ- 

 ence which is amply accounted 

 for by the great discrepancy in 

 girth. 



The limbs were of nearly 

 equal length and there was no 

 such shortening of the fore-arm 

 or elongation of the thigh as in 

 ]Toxodon, and so the descent 

 of the backbone forward, which 

 gave such grotesqueness to the 

 skeleton of the latter, was far 



Fig. 238. -Left p7s of ^Toxodon. La l^SS prOUOUnced. The Umb- 



Plata Museum. Cal, calcaneum. bonCS WCrC rather slcudcr, iu 



As., astragalus. N., navicular. . , . . ^•^ 



Cn. 1 and 2, coossified internal and SlZe and prOportlOUS UOt Uullke 



middle cuneiforms. Cn. 3, external ^hoSC of a tapir, but lu StrUC- 

 cuneiform. Cb., cuboid. 



ture very like the very much 

 larger and more massive ones of ]Toxodon. The bones of the 

 fore-arm were separate, but those of the lower leg were coossi- 

 fied in the same exceptional manner as in the Pampean genus, 

 that is, the upper ends, but not the lower, were fused together. 

 The thigh-bone was not flattened, but had the normal cylin- 

 drical shaft and a conspicuous third trochanter. The feet, 

 in which the digits were already reduced to three, were ex- 



