1877.] 577 [Cope. 



TUDITANUS TABULATTJS, Sp. nOV. 



This species is indicated by a speciniea which includes a cranium, and 

 the anterior part of the vertebral column. It is very well preserved on a 

 block of shale, on both faces, and exhibits the constituent pieces of the cra- 

 nium, the vertebraj, one of the thoracic shields with probable ribs. In all 

 respects it conforms to the genus Tuditanus in characters ; presenting a 

 broad, flat head ; osseous vertebrae and ribs ; thoracic shields present, and 

 abdominal chevrons probably absent. The last character is not abso- 

 lutely assured, since the posterior two-thirds of the vertebral columns are 

 wanting. 



The cranium is wider than long, and the muzzle is broadly rounded. 

 The orbits are wide ovals, and their posterior borders fall little behind the 

 transverse line dividing the skull equally. The interorbital width equals 

 the longitudinal diameter of the orbit. The posterior outline of the cra- 

 nium is truncate in a straight, transverse line between the prominent epi- 

 otic angles. The distal extremities of the quadrates do not project so far 

 backwards as the epiotic angles, and are still further removed from a trans- 

 verse line marking the extremities of the occipital condyles. In this re- 

 spect this species presents a strong contrast to the Pelion lyellii, where the 

 ends of the quadrates extend posterior to the latter points. The composi- 

 tion of the superior cranial walls much resembles that of the Tuditonu^ 

 radiatus. The epiotics are large bones, longer than wide, and present 

 outwards strong angles, which correspond with the horns of Ceraterpeton. 

 They enclose between them the posterior portion of the parietal, and the 

 supra-occipital. The latter is a transverse bone, and not quite symmetrical 

 in the specimen, one end having a greater antero-posterior extent than the 

 other. The parietal is the largest cranial bone, is undivided, and is pierced 

 by a median foramen behind the centre. Its general form is broadly wedge- 

 shaped, the lateral borders expanding in front of the fontanelle, and con- 

 tracting between the epiotics. The frontals are distinct and rather narrow. 

 The post-frontals are rather large, are in close connection with the parie- 

 tal on one side and the jugal on the other, and send a point backwards be- 

 tween the epiotic and sup rate mporal. The jugal widens fan-shaped back- 

 wards, joining two bones distally, a superior and an inferior. The former 

 is the supra-temporal, but whether the inferior is quadratojugal or squa- 

 mosal, I cannot determine. The boundaries of the bones of the extremity 

 of the muzzle are not distinct. 



The sculpture of the surface of the cranium consists of parallel ridges 

 which are separated by grooves equal to them in width. The ridges radiate 

 inwards on the epiotics and frontals, and outwards on the squamosal, and 

 are transverse and interrupted on the supraoccipital. The lateral thoracic 

 shield is covered with a similar sculpture of uninterrupted somewhat 

 radiating ridges. The vertebrae are osseous, and rather small compared 

 with the size of the skull. Opposite to the posterior extremity of the pec- 

 toral shields is a pair of slender bones, which are gently expanded and 

 truncate at the extremities. It is not certain whether these belong to the 



