482 PATAGONIAN EXPEDITIONS I PALEONTOLOGY. 



opening into the orbits. The alisphenoid has a broad, horizontal surface, 

 internal to the squamosal, which differs from that of Dolichotis in its greater 

 size and in the presence of a large foramen ovale, which in the modern 

 genus has coalesced with the foramen lacerum medium. 



The mandible does not differ in any important respect from that of 

 Eocardia. 



Two of the skulls have considerable parts of the skeleton associated 

 with them, unfortunately including but few vertebrae and no ribs or parts 

 of the sternum. The atlas and axis are so like those of Eocardia as to 

 require no description. The lumbars are larger than in the latter and 

 have broader spines and transverse processes, being in all respects, except 

 for the prominence of the anapophyses, more like those of Dolichotis, 

 though the neural spines are more slender and more strongly inclined 

 forward. The sacrum differs from that of Eocardia only in its larger size. 



The scapula (Plate LXIX, fig. 13) is not only larger than in Eocardia, 

 but of a somewhat different shape, being broader in proportion to its 

 length and with more convex coracoid and suprascapular borders ; the 

 acromion is more recurved and the metacromion more slender ; the neck 

 is more contracted ; the coracoid is large and prominent, but is curved so 

 directly inward as to be concealed when the scapula is seen from the side. 

 In both of the Santa Cruz genera the acromion is considerably larger than 

 in Dolichotis, descending below the level of the glenoid cavity. 



So much of the pelvis as is preserved resembles that of Eocardia. 



All of the limb-bones are larger than in Eocardia, as compared with 

 the size of the skull, but the disparity in the length of the fore and hind 

 limbs is even greater, a marked difference from Dolichotis. The humerus 

 (PI. LXIX, fig. 14), though very like that of Eocardia, differs in the 

 less developed deltoid crest and in the wider distal end, due to the greater 

 prominence of the internal epicondyle ; in the trochlea, the median con- 

 vexity for the head of the radius is shifted somewhat farther toward the 

 outer side, and the supratrochlear foramen is larger. 



Of the fore-arm bones only fragments have been obtained ; these are 

 remarkably slender and indicate that the ulna and radius could have had 

 no such elongation as in Dolichotis ; in shape they resemble the corre- 

 sponding parts of Eocardia.' 



The femur (PI. LXIX, fig. 15) is relatively much longer and heavier 

 than in the other Santa Cruz genus and the great trochanter rises higher 



