DINOCERATA. 577 



length of the molar series. The pterygoid process of the palate has two 

 convergent grooves on its inferior surface. The alisphenoid canal is larger, 

 exceeding in diameter both the foramen rotundiim and / ovale. 



The vomer does not unite with tlie superior crest of the palatine bones. 

 The sphenoid flattens out behind the postnareal trough and is co-ossified 

 with the basioccipital. The latter is marked by two oval surfaces at the 

 place of suture, with a slight prominence between. No lower jaw was 

 found with this specimen, but from the contraction of the parts opposed to 

 it, it was evidently very small. 



The teeth are remarkable for the extent of the exposure of their slender 

 roots, as well as their very small size as compared with the size of the 

 animal. The tusk is .slightly turned outward at the tip and the inner face 

 is worn by attrition with some opposing tooth for one-third its length on 

 the posterior third. Tiie superior margin of the enamel on this side is 

 chevron-shaped, the apex being only one-third the length from the extrem- 

 ity. It extends further upward in front and on the outer side, but is worn 

 in an oval patch at the apex of the chevron of this side by contact with the 

 inferior teeth, as above described. The enamel is smooth behind, rugose 

 in front. The crown contracts regularly to a flattened obtuse apex. The 

 fang is hollow for about half its length. The enamel of the molars is nearly 

 smooth. Each one has a strong cingulum fore and aft, which is discon- 

 tinued on the inner and outer faces except in Pm. 1 and M. 2. In the 

 former it is continued on the outer side at the base of the concavity of the 

 exterior face; on the lattei', it is continued round the inner side. The 

 grinding surface of the Pm. 1 is tripodal, and probably composed of a 

 worn crescent and inner tubercle. The others are transverse arrow-shaped; 

 the worn M. I. indicates mature age. M. II. is larger than M III. Its 

 oblique crests have evidently been worn from before. All the molars 

 have three roots, but the posterior pair are united for part of their length 



in all. 



Cranial measurements. 



Length from end nasals to end occipital condyle (3 feet 1.5 inches) 930 



Width jnst behind end nasal shovels 192 



Width in front of horns 132 



Width at base of horns in front 205 



Width behind horns at apex of frontal suture 185 



33 C 



