EDENTATA OF THE SANTA CRUZ BEDS. 



postorbital constriction and usually a profound preorbital fossa in each 

 maxillary. The zygomatic arch is of very constant character throughout 

 the series ; the orbit is widely open behind, the postorbital processes of 

 frontal and jugal being very small or quite absent ; the jugal is loosely 

 attached to the skull and has been lost from the great majority of speci- 

 mens, so that nothing is known of its form, except in the Megalonyc hides, 

 in which it resembles that of Nothrotherium, having a very conspicuous, 

 plate-like, suborbital process, which descends as low as the ventral border 

 of the mandible ; the lachrymal is of mammillary shape and is made very 



FIG. 17. 



Skulls of Santa Cruz Gravigrada, top view, x \. a, Hapalops longiceps; b, H. nteti- 

 meyeri ; c, Megalonychotherium atavus ; d, Eucholoeops fronto ; e, Analcimorphus giganteus ; f. 

 Schismotherium fractwn ; g, S. splendens ; h, Planops magnus. 



conspicuous by being placed upon the prominent zygomatic process of the 

 maxillary ; the foramen is also large and conspicuous, resembling that of 

 Nothrotherium in shape and position. The hard palate may have par- 



