DINOCERATA. 591 



anterior crest, rise into cusps. At the middle of the anterior base of the 

 anterior transverse crest there is a tubercle, which represents the anterior 

 limb of the anterior V in Coryphodon. Tlie crowns of the premolars are 

 broken away in the specimen. 



The alveoli of the incisors are flat, and are directed forwards at an an- 

 gle of only 20° from the horizontal until near their orifices, where the angle 

 is greater. The roots of the incisors are thus curved upwards and forwards. 

 There is but little space between the anterior alveolus and the anterior angle 



of the symphysis. 



Measurements. 



M. 

 Length from anterior edge of symphysis to anterior base of canine flange 074 



Width of symphysis below at bases of lateral flanges 032 



Depth of symphysis between bases of lateral flanges 040 



Width of symphysis above between posterior incisors 017 



Length of bases of posterior five molars 148 



Length of bases of true molars 110 



Diameters crown, M.ii^'^"*"»P''«*''"°'^ O^^ 



< transverse in front 020 



Diameters crown, m. iii | ^°*«''«'P°^t'="°' ^'^^ 



I transverse in front 025 



Width of ramus at posterior edge of M. iii 040 



Although the crowns are somewhat worn, the enamel is wrinkled in- 

 termediately between coarse and fine. 



It may be remarked here that it is by no means certain that the other 

 species here included under the head of Uintatherium have the number of 

 incisors ascribed to the U. robustum. 



Ujntatheeium lacustee, Marsh. 



fDinoeeras lacustris, Marsh, I. c, October, 1872 (published September 27, 1872). 

 Plate xxxvi, figs. 3-8. 



I have the occipital and parts of the parietal and squamasal bones, 

 with some teeth of a specimen which I found together, and which I refer 

 doubtfully to this species. Parts of the same cranium were sent to Pro- 

 fessor Marsh by his collector, who left in the rock the fragments which I 

 afterward procured. Professor Marsh's description of Dinoceras lacustris 

 followed soon after, and his measurements agree with those of the speci- 

 mens obtained by me. 



The species is distinguished from its congeners, apart from its smaller 

 size, by the large size of teeth. These are nearly as large as those of Loxo- 



