DINOCERATA. 573 



is altered into Tinoceras anceps). As no characters whatever were assigned 

 to it on either of these occasions, it had no value in zoological nomencla- 

 ture 



Three species of this genus are known to me, the L. cornutiis and the 

 L. gakatus, which are represented in my collection, and the L. spkrianus, 

 which is founded on a skull preserved in the museum of Princeton Uni- 

 versity, New Jersey. The last named was as lai'ge an animal as the two 

 others, and had a very elongate skull with weak horns and narrow, high 

 occiput. Its median horns are situated .well anterior to the orbit, and its 

 zygomatic fossa is remarkably small. It was discovered by the Princeton 

 scientific exploring party at the same locality that produced the other 

 species, viz., the Mammoth Buttes of Western Wyoming. 

 The three species may be distinguished as follows : 



Median horns triangular in section, with internal tuberosity, and above 



orbits ; occiput narrow L. cornutus. 



Median horns subquadrate in section without internal tuberosity; occi- 

 put and nasal tubercles wide L. galeatus. 



Median horns subround and without tuberosity, in front of orbits; occi- 

 put and nasal tubercles nai row L. spierianus. 



Messrs. Scott, Spier, and Osborne, of Princeton, have published a 

 description* of the lower jaw and teeth of a species of Loxolopliodon, which 

 they identify with the L. cornutus, which was derived from the locality and 

 horizon of the species above mentioned. They show that the descending 

 flange of Uintatherium and Bathyopsis is only represented by a convex ridge 

 on each side of the symphysis. They point out the characters of the denti- 

 tion, which are remarkable. The molars much resemble those of Bathyop- 

 sis. The canines and incisors are alike in form, and in a continuous series. 

 The crowns are compressed so as to be extended anteroposteriorly, and ai-e 

 deeply emarginate, so as to be bilobed, the lobes with subacute edges. 

 This form of incisors is unique, resembling only remotely the large median 

 incisors of certain Insectivora. Eesemblance to mammals of the same type 

 may be traced in the molar teeth. 



" American Journal of Science aud Arts, xvii, 1879, p. 304. See review of this paper in American 

 Naturalist, 1879, p. 334, where some corrections are made by the writer. 



