Hatchkr : Little Known Fossil Vertebrates. 131 



ridges being filled in with smaller plates. The exact outline of some 

 of these smaller plates cannot be determined from our specimen. A 

 figure of a portion of the dermal impression is shown in Plate I, Fig. 

 8. The material was found by the writer in the Ceratops beds of the 

 Upper Laramie, about three miles north of the mouth of Doegie Creek, 

 in Converse County, \\'yoming. 



Class MAMMALIA. 



Order UNGULATA. 



Suborder Artiodactyla. 



Leptochoerus quadricuspis, sp. nov. 



The type of the present species (No. loo) consists of the right 

 maxillary with P.^ and i and M.i, ^, and ^ in position and in an ex- 

 cellent state of preservation. It was found by the writer in a small 

 exposure in the lower Oreodon beds about half a mile west of 

 south of the Brewster and Emmons Ranch, on Warbonnet Creek, in 

 Sioux Co., Nebraska. Associated with the type specimen, but evi- 

 dently belonging to different individuals, were found other remains of 

 Leptoclmrus, consisting of an isolated tooth, M.^ (No. loi), a frag- 

 ment of a left ramus (No. 102) with AL , -^, -^, a. portion of a right 

 ramus (No. 103) with M.y, ^, ^-and P.^ and the alveoles of P. -3. The 

 last mentioned specimen (No. 103) may be taken as the collateral 

 type of the species. 



The present species chiefly differs from Z. spectabilis Leidy,® the 

 type of the genus, in size, it being a third smaller than the latter, 

 as will be seen by a comparison of the measurements given here with 

 those of Leidy published in his original description. A comparison 

 of the specimens shows other structural differences as well. From L. 

 gracilis of Marsh' it is distinguished by a greater complexity of tooth 

 structure, and, more especially, by the structure of P. -2- and M.i and ^. 



In the type of the new species P.^ is the more prominent tooth of 

 the series. Its crown is triangular in outline and bears four distinct 

 cusps, which have suggested the specific name. Of these cusps three 

 are external and one internal. Of the three external cusps, the one in 

 the middle is much the larger, and it is situated directly opposite the 

 internal cone, which latter is of about the same prominence as the an- 



8 See Proc. Acad. Nat. Sci. Phila., p. 88, 1856. 



'See Am. Jour. Sci., Vol. XLVIII, Sept, 1894, pp. 271-273. 



