EDENTATA OF THE SANTA CRUZ BEDS. 



139 



more tubular shape ; the condyles are larger and more elevated above the 

 plane of the teeth ; the forehead is much more inflated and rounded by 

 the development of the frontal sinuses and has no depression in the 

 median line ; the descent of the upper profile from the forehead to the 

 muzzle is very much steeper and more abrupt and the postorbital con- 

 striction is better marked, while the dorso-ventral diameter of the skull is 

 everywhere greater; the rostrum is much shorter, broader and less taper- 

 ing, and there is no preorbital fossa on the maxillary ; the vertical height 

 of the posterior nares is very much greater (cf. Plate XXIII, fig. 5 with 

 Plate XXVII, fig. i). The zygomatic arches are shorter, but curve out 

 more boldly from the sides of the skull, making the temporal foramina 

 wider ; the dorso-ventral breadth of the jugal is greater, its ventral border 

 is much more steeply inclined downward and forward and its postorbital 

 process is much better developed, while that of the frontal is less so ; the 

 great descending suborbkal process of the jugal and maxillary is decidedly 

 longer and has a distinct backward inclination. The hard palate is rela- 

 tively broader and is much less deeply incised by the posterior narial 

 opening. 



The bones of the skeleton agree in almost every detail with those of 



the preceding species. 



MEASUREMENTS. 



Upper dentition, length 094 



, length (i. e., antero-posterior diameter) .003 5 



" width (i. e., transverse diameter) 005 



A, length 0065 



" width OO4S 



1, length 01 2 



" width - .007 



, length oio 



" width 007 



Skull, length in median basal line. .,..?. 130 



" extreme length ? .146 



Cranium, length to anterior rim of orbit . .107 

 width at postorbital con- 

 striction 042 



Cranium, width across zygomatic arches .112 



Zygomatic arch, length 069 



" of suborbital 



process 050 



Occiput, height 042 



width at base 065 



Rostrum, length from infraorbital fora- 

 men ? .036 



Rostrum, width at infraorbital foramen .047 



Palate, length in median line ? . i oo 



" width at 1 017 



" " " 8. 023 



Dorsal tube, length 146 



Sixth thoracic, width of anterior face . . .026 

 First lumbar, width of posterior face. . .0225 

 Second " " " anterior face ... .023 



Second caudal, length of centrum 0325 



" " width of anterior face . .0225 

 " " height (including cen- 

 trum) 052 



Second caudal, width over transverse 



processes 130 



Third caudal, length 036 



" " width of anterior face ... .023 

 " " " over transverse 



processes 115 



