594 GEOLOGICAL SURVEY OF THE TERRITORIES. 



lu comparison with jMarsh's description of his P. laticeps, the measnre- 

 ments are all hirger,and the enamel is as rugose as in L. ?Hry'or, instead of 

 smooth. The shortening of the premolar series is greater in P. dlacomis ; 

 tlius in P. laticepH the two sets of molars are related as 49 mm. to CI ; 

 in the present one, as 100 : 05 ; were the proportions similar, the length 

 of the premolar series shonld be GO mm. 



From Henry's Fork of Green Eiver. 



LlMNOHYUS FONTINALIS, Cope. 



Pdlwosyops fontinalis, Cope ; Proceedings of American Philosophical Society, 1873, 



January 31. 



The smallest of the tapiroids of this series, being about the size of a 

 dog. It is represented especially by a considerable part of the cranium 

 of an individual in which the last superior molar is not quite protruded, 

 but with the other molars and last premolar of the permanent dentition 

 in place. The enamel of these teeth is in accordance with the age, deli- 

 cately rugose, and while the cingulum is present fore and aft, it is want- 

 ing internally and externally. The anterior median tubercle is present 

 on all the true molars, and the bases of the acute inner cones are in 

 contact. The sagittal crest is truncate, and the squamosal portion of 

 the zygoma very stout. The nasal bones are together very convex in 

 transverse section. 



Measurements. 



M. 



Length of true molar series, (2.75 inches) 0.067 



Length of last iiiolar 025 



Wicitlj of last molai.- 026 



Length of penultimate molar 026 



Length of penultimate molar 026 



Depth squamosal process 025 



Found by the writer on a blufif on Green Elver, near the mouth of the 

 Big Sandy, Wyoming. 



HYRACHYUS, Leidy. 



Geological Survey of Montana, 1B71, p. 360. 



This genus was originally described by Leidy from portions of skele- 

 tons of individuals from the Eocene Tertiary of Wyoming. He recognized 

 it as related to the Lophiodon of Cuvier in dentition, and as sharing with 

 characters of that Eocene genus peculiarities which belong to the exist- 

 ing genus Tapirus. 



Having obtained a large series of remains of this genus, including 

 more or less numerous portions of six species with nearly complete 

 skeleton of H. eximius, Leidy, I propose to give such an account of its 

 osteology as will place its relations on a certain basis. 



The .characters which distinguish its dentition from those of the allied 

 genera are as follows : 



Tapirvs, Briss. Lower jaw : Third molar two-crested ; three premolars, 

 the third and fourth with two transverse crests. Upper jaw : Seven 

 molars, first with an inner heel tubercle j other premolars with two 

 transverse crests. 



Eyraehyns, Leidy. Loicerjaw : Third molar with two crests ; four pre- 

 molars, third and fourth with one transverse and one longitudinal crest. 

 Upper jaic : Seven molars, first without interior heelj premolars with 

 two transverse crests. 



