454 Bulletin American Museum of Natural History. [Vol. XIX, 



The cephalic shield is composed of eleven plates in four 

 rows, arranged in the following order from the anterior to the 

 posterior end: 2 in the first, 3 in the second, 4 in the third, 

 and 2 in the fourth rows. Each plate has a central pit which 

 is of pronounced character in the two median plates of the 

 third row. These pits have a circular shape, with raised 

 margin, very rugose sides, and a small cone at the bottom of 

 the pit. 



The sutural borders present a prominent ridge, very rugose, 

 with deep paired holes on either side of ridge, excepting the 

 sutures separating the four posterior median plates which are 

 well defined, but do not show raised edge or holes. 



The outline of the shield is not as circular as in E. petesatus, 

 and the border is more distinctly emarginated at the junction 

 of the first and the second rows. The plates in the first row, 

 also the median plates of the second row, in the present 

 species are smaller than in E. petesatus, while the four pos- 

 terior median plates are relatively larger. 



The teeth differ from those of E. petesatus, especially in the 

 anterior part of the jaw. The first molar is rather large, of 

 elliptical contour, though the grinding surface is broken away, 

 set obliquely to the dental series so that the anterior teeth of 

 the two rows approach each other more closely than any of the 

 following teeth. M^ is larger, less elliptical, and obscurely 

 trilobate, only one internal groove being prominent, with 

 faint indication of posterior internal and external grooves. 

 M^ is much larger and more distinctly trilobate internally. 

 M* is distinctly trilobate, the lobes separated by deep sulci; 

 the anterior lobe in each tooth showing a groove on the an- 

 terior face near the external border. M^'^ are of the same 

 pattern as M*. 



Most of the sutures are obliterated, so that little can be said 

 of the cranial bones or of their proportions. The cranium is 

 broad and depressed. The forehead is flattened and very 

 wide, ending in a distinct postorbital process. The rostrum 

 is very broad at the base, narrowing rapidly to the narial 

 opening. The muzzle is heart-shaped. The zygomatic arch 

 extends out widely from the skull and is very deep, with 



