GEOLOGICAL SURVEY OF THE TERRITORIES. 5G7 



duced in a contracted form beliiud the molar teeth. The two bones in- 

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

 rior snture of the palatine, the foramen palatinum. The posterior 

 nares are not excavated anterior to the line of the posterior 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 iDreniaxillaries are longitudinal and sej)- 

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

 incisivum, 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 suture reaches by an 

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

 rected process which reaches to the end of the anterior third of the iirch 

 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 l^vge foramen incisivum 

 in front, and are therefore deeply furcate. 



The dentition is I. 0; 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 by the pre- 

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

 cranium, which extends upward 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 Loxolojihodon to this genus in a short 

 paper published August 19, 1872, as above cited, with a diagnostic de- 

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

 here retained as the type. I again described it more fully in a paper 

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

 perhaps incorrectly, as indicated by the present paper. The same no- 

 menclature was employed in a paper read before the American 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 previously (February 10, 1872) applied the name 

 Loxolophodon, and included in it the species there called Bathmodon 

 (Loxolophodon) semieinctus., Cope. With further material this appears 

 not to be correct; the Ballimodon scmicinctu& belongs truly to that 

 genus, and is very near to the B. radiaiu^ so that the name Loxolopho- 

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

 the present genus without interference. It was^ moreox-er, 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,)* applied the name Tmoceras to a species {T. grandis) 

 of this genus, and gave a description, in which some of tlie generic 

 characters may have been mentioned. He had previously applied 

 it without description to the Titanotherium f anceps, August 24th, 

 (and 19th, t in an erratum, where Mastodon anceps is altered into Tino- 

 ceras 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, and most of the other papers of Professor Marsh on this 

 fanna, till early in December, 1872. 



t These pax»er8 were not received by me till early in December, 1872. 



