1895.] 443 [Qope. 



Captorhinus Cope, gen. nov. 



Captorhinus angusticeps, sp. nov. 



This species is represented by an imperfect skull with both rami of the 

 lower jaw in place. The superior osseous walls have been mostly lost, 

 leaving a cast of this region ; the walls of the maxillary and mandible, 

 and one side of the temporal region, with the border of one orbit remain. 

 Almost the entire dental series of both sides is displayed, the teeth being 

 split through their centres. 



The head is wedge shaped, with an acuminate and rather elongate 

 muzzle. The orbits are round and very large, the diameter being double 

 the interorbital width, and equal to the length of the muzzle to the 

 middle of the nostril. The teeth increase in length gradually from behind 

 forwards, and the anterior mandibular teeth are inclined forwards at an 

 angle of 45°. The premaxillary teeth have lost their crowns, but from 

 the direction of the alveolfe, it appears that they were not directed pos- 

 teriorly to any conspicuous degree. The posterior teeth of both jaws have 

 obtuse crowns, and the crowns become more and more conic to the front. 

 Nothing can be said of the character of the sculpture, as the surface of 

 the bone, where present, is injured. The characters which distinguish 

 the species as compared with other Pariotichidse, besides those of the 

 teeth, are the followmg: The interorbital width is less; the orbit large, 

 entering the temporal length 1.5 times; and the skull is narrowed pos- 

 teriorly, the width being three-quarters of the length, as in the Parioti- 

 chus aguti. 



Measurements. mm. 



Total length of skull 62 



Width of skull posteriorly 41 



Interorbital width 10 



Diameter of orbit 16 



Elevation of crown of a posterior superior tooth 2.5 



" " " an anterior " " 4 



Length of posterior inferior tooth 2 



" " anterior " " 5 



Depth of cranium at occiput 14 



" " mandibular ramus below temporal roof 10 



From the Permian formation of Texas. 



Pariotichus Cope. 



Proceeds. Amer. Philos. Soc, 1878, p. 508; I. c, 1883, p. 631. Ectocynodon 

 Cope, I. e., 1878, p. 509. 



This genus was established on the smallest known species, the P. 

 hrachyops Cope, in which the premaxillary teeth are unknown. The max- 

 illary teeth display the enlarged median tooth characteristic of the species 

 referred to Ectocynodon, although it is less prominent than in some of the 



