94 0. C. Marsh — Eastern Mlohlppus Beds. 



The maxillary plates of the palate are deeply cleft in front. 

 The anterior palatine foramina open just in front of the second 

 premolars, and long, shallow grooves extend from them to the 

 front of the palate. The nasals are deeply furrowed behind 

 by grooves leading backward to the supra-orbital foramina. 

 The parietal ridges show a rugosity at the points where the 

 horn-cores would later have appeared. The entire length of 

 the skull is about eight inches, and from the front to the end 

 of the molar series is five inches. 



Calops cristatus, gen. et sp. nov. 



The present type specimen is a skull in fair preservation, 

 indicating a fully adult animal, which when alive was about 

 half as large as a goat. In its general form and in most of 

 its characters, this skull agrees so closely with the type of 

 Protoceras as to suggest at once some affinity between the two. 

 The dentition preserved in the premolar and molar series is 

 essentially the same. The high maxillary plates joining the 

 short, pointed nasals ; the deep lachrymal fossa ; and the pos- 

 terior orbit strongly closed behind, all suggest an ally of 

 Protoceras, but the parietal ridges are here elevated into 

 distinct crests, and are without horns. 



This skull when complete was about six inches in length. 

 The distance from the front of the nasals to the junction of 

 the parietal crests is about four inches and a half. The space 

 occupied by the last three premolars and the true molars is 

 about two and one-half inches. 



Thinohyus robustas, sp. nov. 



A new species of this genus is indicated by a nearly perfect 

 skull, which shows many features of interest. It indicates an 

 animal much larger than the type from Oregon, and one 

 slightly superior in size to the existing collared peccary. In 

 many respects, it resembles the latter so much, that it may be 

 considered one of its direct ancestors. 



The present species has the full complement of teeth, forty- 

 four, but the skull has shortened, so that the first upper pre- 

 molar has been crowded inside the canine. The teeth are 

 proportionately larger than in Dicotyles. The last upper 

 molar is smaller than the first or second. The last premolar 

 has two outer cones, and one inside. The space occupied by 

 the three upper molars is one and three-fourths inches, and the 

 extent of the entire dental series is five inches. The whole 

 skull is about nine inches in length. 



Yale University Museum. New Haven, Conn., June 22, 1894. 



