352 GEOLOGICAL SUEVEY OF THE TERKITORIES. 



parently of the same genus, has been described under the name of Anti- 

 lope dichotomy from the tertiary formations of Gers, in France. 



Cosoryx furcatus. — The Niobrara species thus named was about the 

 Bize of the sheep. 



CAMELOPERDALID^E. 



A singular fossil, obtained by Professor Hayden from Dr. Gehrung, 

 of Colorado City, submitted to the writer for examination, leads to the 

 suppositon that it belonged to a large ruminant, probably of the same 

 family as the existing camelopard of Africa. It has been referred to 

 an unknown genus, with the following name : 



MEGACEROPS. 



The genus is based on a skull fragment, of remarkable character, 

 found in Colorado. The fossil calls to mind the wonderful but also ex- 

 tinct Sivatherium of the Sevalik Hills of India. The specimen corre- 

 sponds with that portion of the face of the latter animal which comprises 

 the upper part of the nose, together with the forehead and anterior horn 

 cores. As in Sivatherium, all the bones comprising the specimen are 

 completely coossified, and of great comparative massiveness. The 

 genus was probably the American representative of the Sivatherium, 

 which was the largest of all known ruminants. In its bulk and pro- 

 portions it approached the elephant, and it was provided with two pair 

 of horns and probably a proboscis like the taper. 



Megacerops coloradensis. — The species was not so large as the Sivath- 

 erium giganteum of India, but may be regarded as having been the largest 

 of all the known ruminants of America, recent and extinct. 



AETIODACTYLA. 



Under this ordinal name the writer has included the thick-skinned 

 animals or pachyderms of Cuvier, which have an even number of toes, 

 and has excluded the ruminants of the artiodactyle pachyderms of Pro- 

 fessor Owen. 



SUIDJE. 



The suilline family at the present time is not represented in America 

 by any of the old-w 7 orld genera, nor at any past time, so far as the ob- 

 servation of the writer is concerned, was it inhabited by them. Not- 

 withstanding many reports of discoveries of remains of the hog and 

 the hippopotamus, the writer has as yet seen no undoubted traces of 

 these animals which pertained to the American continents. 



DICOTYLES. 



The peccaries appear to have represented in the western hemisphere 

 the hogs of the other part of the world ; at least the writer has not yet 

 seen fossil remains which appeared to him as indubitable evidences of 

 the existence at any time of an indigenous species of hog in America. 

 At the present time two species of peccary inhabit South America, and 

 one of them, the collared peccary, extends into North America as far 

 as the Red River in Arkansas. 



At an earlier period several species, now extinct, inhabited North 

 America. Professor Hayden found an upper canine tooth of a peccary 

 on the Niobrara River, but its age and reference to a particular species 

 are uncertain. A portion of a skull, found in digging a well, at the 

 depth of thirty feet, in Gibson County, Indiana, indicates a species which 

 has been named Dicotyles nasutus. It was rather larger than either of 



