G. 1, Adams — Extinct Felidce of North America. 429 



LeDgth of the skull, inion to premaxillary border, 260 mm 



" humerus 240 



" tibia _ - 237 



Hopylophoneus insolens Adams. 



The determination of the skeletal characters of H. occidentalis 

 made it apparent that the specimen determined as such by 

 Osborn and Wortman (Bull. Amer. Mus., 1894) is a quite distinct 

 species, and it together with material in the Princeton collection 

 was the basis of this species intermediate between H. robustus 

 and H. occidentalis. As compared with H. robustus the skeleton 

 is much larger, the limb bones being longer but not much heavier, 

 the extremities being relatively smaller. The dental formula is 

 I|C|Pm|Mf 



Length of skull, condyles to premaxillary border, 190 mm 



" humerus 200 



" ulna 212 



" femur. _ 250 



tibia _ 188 



Hoplophoneus oreodontis Cope. 



This species is the type of the genus. It was first described by 

 Cope under the genus 3Iachoerodus, but better material enabled 

 him to separate from that genus. The specimen figured in the 

 series is interesting as supplementing the material already known. 

 This skull (number 10515 in the Princeton collection) differs from 

 that described by Cope in showing the roots of a much reduced 

 pm 2 , thus changing the dental formula of the species If C^-Pm^ 

 M.^. It is the smallest species known from the White River. 



Length of skull, condyles to premaxillary border, 135 1 



:tnm 



Hoplophoneus cerebralis Cope. 



This is the smallest species and the most peculiar. It is the 

 only representative of the genus thus far found in the John Day. 

 It is peculiar in showing a short temporal space, a very convex 

 profile, and a nearly vertical and abrupt occiput. The superior 

 sectorial has a better developed anterior basal cusp than the other 

 species ; in this respect it approaches Machcerodus, as has been 

 noted by Cope. Dentition I 3 /C l /Pm 2 M 1 /. The species is known 

 only from a skull. 



Length of skull, condyles to premaxillary border, 120 mm 



There are thus six species of Hoplophoneus disregarding, H. 

 strigidens Cope, which being known only from a fragment of a 

 canine which presents an unusual form, is not characterized by any 

 features which refer it to that genus rather than any other. The 

 series of skulls figured in Plate XI show a great variation in size 

 and a study of the skeletons shows a like variation. 



BBBHB 



