EDENTATA OF THE SANTA CRUZ BEDS. 305 



MEASUREMENPS. 



Type. No. 9,237. No. 15,590. 



" width (*'. e., transverse diameter) 35 -OOSS -<x>3 



2 , length 0075 .0063 .0063 



" width 0065 .006 .0065 



2-, length 008 .006 .0063 



" width oio .0105 .010 



A, length 0065 .006 -0055 



" width OO9S -Oio .009 



-5-, length 0035 .005 .005 



" width 007 .009 .008 



The skull has certain constant differences from that of S. fracttim. As 

 in the latter, the occiput is low and from it the upper contour of the skull 

 rises quite steeply to the parietal eminence, though the cranium is never 

 so high and dome-like as it often is in S. fracttim ; from the eminence the 

 profile decends very gradually and almost uninterruptedly to the end of 

 the rostrum. The characteristic difference from the skull of the preceding 

 species is best displayed when the skull is viewed from above ; it is then 

 seen to have a narrower and more elongate cranium, with much better 

 defined sagittal crest and temporal ridges, longer, shallower and less 

 abrupt postorbital constriction, shorter and less tapering rostrum. The 

 occipital surface is relatively narrower than in S. fracttim, with thinner 

 and less prominent crest, which, though curved forward between the parie- 

 tals, does not form so deep an embayment ; the foramen magnum is more 

 circular and the condyles less sessile. The parietals are relatively broader 

 and the squamosal is narrower, and its zygomatic process even shorter. 



A fragment of the jugal is connected with No. 9,247 and differs in some 

 respects from that of any other Santa Cruz species in which this element 

 is known, displaying a curious resemblance to the jugal of Glossotherinm 

 as figured by Reinhardt ('79, Tab. I); the anterior end is broadened into 

 a hammer-like head for articulation with the maxillary and lachrymal, then, 

 for a short distance, the bone becomes very slender, expanding again into 

 the plate-like suborbital process, which is narrower than in Glossotherium, 

 but has similar raised borders, with a depression between ; the posterior 

 part of the jugal must have been longer than in the Pleistocene genus, as 

 is shown by the zygomatic process of the squamosal. 



The frontals have less of the hour-glass shape than in S. fradum, owing 

 to the shallowness of the postorbital constriction ; they have a shorter, 

 wider sagittal crest and much more prominent temporal ridges ; anteri- 



