1882.] 458 [Cope. 



double, forming two lines between which the mandibular teeth close. This 

 superior series stands near the external edge of the vomei", palatine and 

 pterygoid bones successively. I have not been able to find any larger 

 teeth in the jaws in this genus. Some fragments mingled with those here 

 described, display such teeth, but I think they pertain to a species of 

 another genus. I know nothing of the limbs of this genus. 



DiPLOCAULUS MAGNICORNIS, Sp. nOV. 



The species is indicated by fragments of a number of crania, and por- 

 tions of several vertebral columns. These were collected at two different 

 localities by Mr, W. F. Cummins. 



The skull is very peculiar in the great extent of the parts posterior to 

 the orbits as compared with the portion anterior to them. The posterior 

 border not being complete, the proportions cannot be exactly given, but 

 the part anterior to the orbits is two-thirds the length of the part extend- 

 ing from their posterior border to near the base of the lateral horn, and 

 one-fifth the distance from the orbit to the extremity of the horn. The 

 part of the border of the orbit preserved indicates that the latter is of fair 

 size. It is separated from the maxillary border by at least its own diame- 

 ter. The external nares are peculiarly situated. They are nearer the 

 orbit than the end of the muzzle, and are close to the maxillary border, 

 being separated from the mouth by a narrow strip of bone only. They 

 are round, open nearly laterally, and are removed from the edge of the 

 orbits by the diameter of the latter. 



The malar or quadratojugal bone is protuberant at the canthus oris and 

 projects laterally beyond the mandible at its posterior part. It also pro- 

 jects beyond the extremity of the quadrate bone. This border is continued 

 as that of the external base of the horn, but the portion which belongs to 

 this element is soon distinguished from the superior element (squamosal) 

 which composes the horn, by a groove. This groove is decurved, and 

 bounds the apex of the element, which is a decurved, low tuberosity. 

 The horn is produced backwards in a horizontal plane, forming a long flat 

 triangle which contracts gradually with straight sides. The apex is nar- 

 rowed, obtuse, and a little incurved. Near and at the extremity the horn 

 is flat above and convex below. 



The maLdibular quadrate cotylus consists of two fossae, which together 

 form an approximate figure oo, of which the internal fossa is the smaller, 

 and opens internally. The external one is nearly transverse. The supe- 

 rior border of the ramus posteriorly is straight. The greater part of the 

 superior aspect is occupied by a huge fossa which opens upwards. 



It is uncertain whether the horns meet at an entering angle on the 

 middle line posteriorly or not, but the width of the base of the horn indi- 

 cates that such is the case. The extremity of the muzzle is depressed, and 

 is broadly rounded. 



The external surface of the skull is sculptured in the form of fossae so 

 distributed that the narrow ridges separating them do not form straight 



