GEOLOGICAL SURVEY OF THE TERRITORIES. ' 5G7 



duced in a coutracted form behind the molar teetb. The two bones in- 

 close a small forameu in this prolongation, and a larger one on the ante- 

 rior suture of tbe palatine, the foramen palatinum. The posterior 

 nares are not excavated anterior to the line of th<^ i)osterior border of 

 the last molars. The palate is deeply concave anteriorly. There is 

 an elongate foramen close to the alveolus of the first premolar, ex- 

 tending anterior to it. The premaxillaries are longitudinal and sep- 

 arated anteriorly for two-fifths of their length, by a large foramen 

 inei.nvum, which they do not inclose. They extend on the side of the 

 muzzle into an acute angle upwards and backwards, and are prolonged 

 forwards above the exterior nares, which the snture reaches by an 

 abrupt descent. The maxillary supports the malar on a posteriorly di- 

 rected process whicth reaches to the end of the anterior third of the arch 

 below, half that distance on the side, and is bordered by a narrow strip 

 of the malar on the inner side, as far as the anterior boundary of the 

 orbit. The premaxillaries do not inclose the very large foramen incisivum 

 in front, and are therefore deei)ly furcate. 



The dentition is I. ; C, 1 ; P. M. 4 ; M. 2. The canine is a tusk of 

 compressed form, with anterior and posterior cutting edges, and a 

 strong posterior curvature. Its fang is embraced one-third hy the i>re- 

 niasillary bone, and is inclosed in a rib-like swelling of the sides of the 

 cranium, which extends npward and backward. The premolars are well 

 worn, and have transverse cordate surfaces of attrition. These have 

 probably resulted from the wearing down of a chevron of two crests 

 converging inwards, in some with an inner tubercle. On the molars this 

 crescent is represented by a V, with the apex inwards; on the last, the 

 inner tubercle is at one side (the posterior) of the apex. 



Name. — I first applied the name Loxolopkodon to this genus in a short 

 paper iniblished August 10, 1872, as above cited, with a diagnostic de- 

 scription ; the L. corniitus was there cited as the first species, and is 

 here retained as the type. I again described it more lully in a pai»er 

 published August 22d, citing IJohasiIe7is (August 20th) as a synonym, 

 perhaps incorrectly, as indicated by the present paper. The same ne- 

 menclature was employed in a paper read before the ximerican Associa- 

 tion for the Advancement of Science, held at Dubuque, commencing 

 August 23, 1872. 



In the paper of August 22d, I regarded this genus as identical with 

 that to which I had i)reviously (February 1(J, 1872) applied the name 

 Loxolopkodon, and included in it the species there called Bathmodon 

 {Loxolopkodon) semicinetus, Cope. With further material this appears 

 not to be correct; the Bathmodon se7)iieinctiis belongs truly to that 

 genus, and is very near to the B. radians, so that the name Loxolopko- 

 don becomes a synonym in this connection, and may be used again for 

 the present genus without interference. It was, moreover, not de- 

 scribed at the former date, and had no proper claim to recognition. 



Professor Marsh, in the American Journal of Science and Arts, 1872, 

 (September 21,)* ap})lied the name Tinoceras to a species (T. grandis) 

 of this genus, and gave a description, in which some of the geneiic 

 characters may have been mentioned. He had ])reviously ai)plied 

 it without description to the Titanotkerium ? ariceps, August 24th, 

 (and ll)th,t in an erratum, where Mastodon anceps is altered into lino- 

 eeras anceps.) As no characters whatever were assigned to it on either 

 of these occasions, it had no value in zoological nomenclature. 



* I did not receive this, iiud most of the other papers of Professor Marsh oa this 

 fauna, till early iu Deeemiter, 1B7:2. 



t These papers were uot received by uie till early in December, 13T2. 



