EDENTATA OF THE SANTA CRUZ BEDS. 1 9 



(No. 15,566) they are hardly noticeable. Owing to the less inflated form 

 of the forehead, the descent to the rostrum is less abrupt than in the recent 

 genus. Anteriorly, the frontals are quite deeply notched to receive the 

 narrow nasals, and there are long, pointed nasal processes. 



The nasals are very elongate, much more so than in Tatu, but other- 

 wise of quite similar shape. Narrow posteriorly, they broaden forward, 

 until near the anterior end they cover the whole width of the rostrum and 

 curve farther down upon its sides than in the recent genus. Everywhere 

 they are convex transversely and, for much of their length, they are con- 

 vex longitudinally also, but anteriorly, owing to the slight upturning of 

 the end of the rostrum, they become somewhat concave in this direction. 

 Dorsally, the nasals project well beyond the premaxillaries, though not so 

 far as in Tatu, and their free ends are abruptly truncated and rounded, 

 not bluntly pointed as they are in the latter. The anterior nares are very 

 oblique and have nearly the same shape as in the recent genus, but are 

 rather lower and wider. 



The premaxillaries are likewise much longer than in Tatu, but do not 

 rise so high upon the sides of the rostrum, of which they form less and 

 the nasals more than in the recent genus. Posteriorly, the premaxillaries 

 are very low and are extensively overlapped by the maxillaries. On the 

 ventral side, the anterior ends of the premaxillaries are curiously similar 

 to what is to be seen in the modern genus : there is a short median pro- 

 cess and each bone has two lateral notches, the outer one above and a little 

 in advance of the inner. The palatine processes are narrow, somewhat con- 

 vex and of almost uniform width throughout, though broadening slightly 

 toward the hinder end ; they curve uninterruptedly into the sides of the 

 tubular rostrum. The incisive foramina are elongate and very narrow 

 slits, separated by a slender spine and continued posteriorly by long, 

 shallow grooves. 



The maxillaries, like all the bones that enter into the formation of the 

 rostrum, are more elongate than in Tatu, while the facial portion is much 

 less inflated, so that externally it projects much less beyond the plane of 

 the teeth and the forward contraction of the rostrum is more gradual. 

 However, this facial region is decidedly inflated and indicates the presence 

 of large antra. The zygomatic process is much shorter than in the exist- 

 ing genus and less expanded vertically, nor does it extend beneath the 

 jugal, with which it has a very short and almost vertical suture. The in- 



