EDENTATA OF THE SANTA CRUZ BEDS. 103 



1 has a greater antero-posterior diameter than in P. pumilus. The groove 

 on the outer face of the crown is more distinct in a to & than in the corre- 

 sponding teeth of the latter species and is more nearly in the middle of 

 the outer side. 



The skull has several differences from that of P. pumilus ; the cranium 

 is somewhat shorter and the rostrum longer proportionately ; the cranium 

 contracts forward more rapidly to a more definitely marked postorbital 

 constriction, but is less vaulted, so that the descent at the forehead is 

 somewhat less steep. The occipital crest is more prominent, making the 

 temporal fossae more concave, and the sagittal crest is much better devel- 

 oped and extends forward upon the frontals, a difference which is demon- 

 strably not due to age, but may possibly be due to sex. The elongation 

 of the rostrum is particularly well marked in the dorsal region, where the 

 nasals project freely beyond the edge of the premaxillae and the dorsal ends 

 of the ascending rami extend much farther beyond the alveolar portion of 

 the premaxillse than in P. pimiifas ; the median spine-like projection from 

 the line of suture between the two premaxillaries is very much more 

 prominent than in the latter species. 



MEASUREMENTS. 

 Upper dentition, length 036 1, length 002 



" " " ^-i inclusive .. .032 Skull, length on median basal line 090 



i, length (i. c., antero-posterior diam- " extreme length 112 



eter) 0035 Cranium, length to anterior rim of orbit .070 



1, length 004 Face, length 042 



A, " 005 Occiput, height . . . . , 042 



A, " 0045 Zygomatic arch, length 05 1 



, " 0043 Mandible, length 063 



4 , " 0035 " depth below ^ 014 



PELTEPHILUS GRANDIS Moreno & Mercerat. 



(Plate XVI, fig. 6.) 



Peltephihis grandis M. and M.; Rev. Mus. de La Plata, T. II, 1891, p. 62. 

 Peltepliilus giganteus Amegh.; Enum. synopt. d. Mamm. Foss. de Pata- 



gonie, 1894, p. 179. 

 Peltepliilus giganteus Lydekker; Anales del Museo de La Plata, T. Ill, 



1894, p. 70. 



The largest species of the genus, characterized not only by its large 

 size, but also by the form and sculpture of the postero-median scute of the 



