Cope.] ^0 [Feb. 21, 



The basis is very narrow and lenticular ; a short distance above it the 

 outer side is convex. The anterior and posterior extensions of the base 

 differ ; the one is thinner, the other more massive and with a shallow 

 groove above its commencement. The latter may be posterior. If so, 

 the compressed apex of the horn-core sends down a rib outwardly to the 

 anteriorly and one inwardly, which disappears on the convex base. The 

 general form is spatulate with the apex expanded obliquely across the lat- 

 eral crest, and regularly rounded in superior outline. Its anterior face 

 is flat, the posterior convex ; its surface is grooved by very small blood 

 vessels. 



As compared with the posterior horn-core of Loxolophodon cornutus, 

 there is every difference. That is continuous with one margin of the 

 crest ; this, erect above it ; that has a round base, this a lenticular one. 

 It is more like that of XI. mirahile, which I only know from Marsh's figure, 

 but abundantly distinct. It is much more elongate, especially above the 

 posterior ? part of the crest, and is flattened, and without the triangular 

 section of that species. 



Measurements of Horn-core. 



M. 



The total length above crest (5.5 inches) 0.135 



" " " " base (7£ inches) 180 



Width across apex (in front) 095 



Thickness across apex (in front) '. 028 



" at bas? 040 



It is not certain that this horn may not belong to the E. pressicornis, if 

 it be a posterior core, of which, however, I am not yet entirely sure. In 

 that case the name furcatus, under which it was first described, becomes 

 a synonym of E. pressicornis. 



UINTATHERIUM. Leidy. 



Proceedings Academy Natural Sciences, Philadelphia, 1872, page 1G9 

 (published early in August). Dinoceras, Marsh, Amer. Journ. Sci. Arts, 

 1872. October, 1872 (published September 27). 



This genus resembles the last in its general proportions, but differs in 

 its more elongate cervical vertebrae. The centra of these are flat at both 

 extremities, but have not such a marked elephantine abbreviation as 

 seen in the two genera above described. This enabled the head to 

 approach the ground more nearly, and as the limbs were shorter in some 

 of the species, they no doubt modified the length of the proboscis, if 

 present. 



Several names have been applied to this genus. Professor Leidy' s 

 name here employed, bears date early in August, but of the precise day 

 I am not informed. Professor Marsh, in the Am. Jour. Sci. and Arts, 

 1872 (Sept. 21st), applied the name Tinoceras to a species (T. grandis) 

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



