ABSTRACTS OF PAPERS 153 



NOTES ON THE AMERICAN PLIOCENE RHINOCEROSES 

 BY W. D. MATTHEW 



(Abstract) 



Three genera of rhinoceroses occur in our Pliocene — Aphelops, Peraceras, 

 and Teleoceras. Tliey are distinct in the proportions of the skull, character 

 of the horn-cores, upper and lower tusks, reduction of premolar teeth, hypso- 

 donty of molar teeth, and by the proportions of limbs and feet. Although 

 some or all may be derived from Old World ancestry, these genera are limited 

 to North America and are distinct specializations from any of the various 

 rhinoceros phyla of the Old World. They became extinct apparently before 

 the end of the Pliocene. 



New Upper Eocene mammals from Utah were then very briefly de- 

 scribed by Mr. Peterson, who had prepared a much longer paper on the 

 subject. 



NEW ARTIODACTYLS FROM THE UPPER EOCENE OF THE UINTA BASIN, UTAH 



BY O. A. PETERSON 



{Ahstract) 



The paper is an abstract taken from the general report on the Vertebrata 

 of the Upper Eocene of the Uinta Basin, Utah, now ready for publication. 



A number of new genera of the subfamily Homacodontinse are first taken 

 up. Secondly, it gives a short description of an American Anoplothere and its 

 relation to Diplohune of Europe. Thirdly, a brief description and complete 

 restoration of a new oreodont from the Upper Eocene. And fourthly, a de- 

 scription of a new Eocene hypertragulid and a review of the relationship 

 between the Uinta and the Oligocene genera of the HypertragulidfP. 



A paper on stratigraphy and invertebrate paleontology was next in 

 order and was presented by the senior author. Discussed by Messrs. 

 Dickerson and Grabau. 



MARINE OLIGOCENE OF THE WEST COAST OF NORTH AMERICA 

 BY B. L. CLARK AND RALPH ARNOLD 



(Ahstract) 



A general survey of the known data concerning the paleogeography, climatic 

 conditions, and faunal relationships of the Oligocene as found in California, 

 Oregon, Washington, and Vancouver Island. 



The marine Mesozoic and Tertiary sediments of the West Coast were, for 

 the most part, laid down in broad geosynclinal troughs, the axes of which 

 paralleled that of the present ranges. The Tertiary sediments accumulated in 

 these slowly sinking troughs to an enormous thickness. Koughly estimated, 

 there are at least 40,000 feet of sediments of Tertiary age in the Coast Ranges : 

 of this fully 10,000 feet belong to that period of time which is here referred 



