GEOLOGICAL SURVEY OF THE TERRITORIES. 593 



LIMNOHTUS, Leidy. 



Proceedings Academy Natural Sciences, Philadelphia, 1872, p. 242, Palwosyops, Marsh, 

 Amer. Journ. Sci. Arts, 1872, p. 122, not of Leidy, 1871. 



This genus only diifers from the last in possessing two conic tubercles 

 of the inner series on the last superior molar, instead of one, a charac- 

 ter first pointed out by Marsh. 



LiMNOHYUS PALUDOSUS, Leidy. 



Proceedings Academy of Natural Sciences, Phialdelphia, 1870, p, 113, not of later 



descriptions. 



My expedition did not obtain any specimens which I can as yet certain- 

 ly refer to this species. The measurements given by Professor Marsh for 

 his Paheosyops laticeps approach very nearly to this one. Thus the 

 width of the crown of the last superior molar is M. .038; in P. laticeps 

 .040 ; in L. diaconus, Cope, it is .047. 



LiMNOHYUS DIACONUS, Cope. 



Falceosyops diacomis, Cope, on some Eocene Mammals obtained hy Hayden's Geological 



Survey of 1872, 1873, p. 4. 



The species is as large as the .Palceosyops major of Leidy, but differs 

 in the relative proportions of the teeth. Thus the last three molars have 

 the same antero-posfcerior length, while the space occupied by four pre- 

 molars is shorter. The anterior and posterior cingula of the true molars 

 are very strong, but it is not well marked on the inner side between the 

 cones. The latter are acutely conic, and the median anterior tubercle 

 is strongly developed. Although the wearing of -the teeth indicates 

 maturity, the enamel is coarsely and obtusely rugose. The fourth pre- 

 molar differs from that of L. major in its smaller size relatively and 

 absolutely, and in the presence of a prominent vertical tubercle on the 

 outer face, rising to the angle of the deep notch between the lobes. The 

 third i^remolar is as wide as the fourth, and about as large as the cor- 

 responding tooth in L. major, but different from it in the absence of 

 tubercle and ridge that mark its external face. The first premolar has 

 two roots, and the canine is large and stout. 



This large Palseotheroid is represented by parts of the two maxillary 

 bones, which present the crowns of the third and fourth premolars, and 

 of the second and third true molars, with the bases of the other molars 

 and premolars. 



Measui-ements. 



M. 



Length of entire molar series 0. 1710 



Length of true molars 1060 



Length of last molar, (crown) 0420 



Width of last molar, (crown) - -.. . 0473 



Length second molar 0350 



Length fourth premolar 0260 



Width fourth premolar 0260 



Width third premolar : 0200 



Length third premolar 0200 



Diameter of basis of canine 0263 



The L. paludosus, Leidy, is similar to this species in the rugosity of the 

 enamel of its teeth, but appears by the measurements to be distinctly 

 smaller, so as to relate to it about as to P. major. 

 38 G s 



