THE TEMNOSPONDYLOUS AMPHIBIA. 1 83 



" Represented by a considerable portion of the face and muzzle of a single individual. 

 A portion of the left mandible, supporting three teeth, remains in place, and almost the 

 entire boundary of the right orbit is preserved. 



" The fragment indicates a much larger species than any other referred to the genus, 

 and, next to the Leptophractus obsoletus, the largest of the Batrachians of the Ohio Coal 

 Measures. Without more complete remains, it is not easy to determine its generic relations 

 finally. 



"The form of the head is probably elongate, and the muzzle neither very obtuse nor 

 elongate. The orbit is rather small, and near the middle of the length of the specimen, 

 which is, however, incomplete at both ends. The sculpture of the surface of the head pos- 

 terior to the orbits, as well as round their borders and for some distance in front of them, 

 consists of a rather coarse pitting. On the middle line, between the orbits and on the muz- 

 zle, the intervals become narrower, and are confluent into transverse ridges or a delicate 

 reticulation. The surface of the mandible displays a coarse reticulation. 



" The teeth are stoutly conic, and with delicately striate grooved cementum. They are 

 slightly recurved. 



' ' This species differs from the T. radiatus and T. obtusus in the absence of the area into 

 which the sculpture is thrown. 



" Longitudinal diameter of orbit, 19 mm.; length of alveolar border supporting three 

 teeth, 13 mm. ; diameter of base of tooth, 3 mm. ; eight pits in 10 mm. 



" Dedicated to Professor T. H. Huxley, facile princeps among English systematists, and 

 an important contributor to the knowledge of the extinct Batrachia." 



The following discussion of the cranial elements, based on the writer's studies 

 (462, 465) of the type, may be appended to Professor Cope's original description. 

 -The sutures bounding a few of the elements have been made out in part. The 

 prefrontal element seems well assured. It lies well in front of the orbit, much as in 

 the skull oiCapitosaurus from the Keuper of Europe. The lacrimal is, apparently, 

 a very large bone, though its entire extent is not assured. 



The maxilla is a long, narrow element on the border of the skull. The suture 

 separating this from the lacrimal and jugal is quite clear. The teeth which the 

 maxilla undoubtedly bore are hidden by the remains of the mandible, which lies 

 partly on the edge of the skull. The jugal is a very large element and its boundaries 

 seem well assured. Its size and relations recall the condition in Capitosaiirus. It 

 forms a part of the external boimdary of the orbit. The lateral suture of the post- 

 orbital is evident and is, as shown in the figure, somewhat curved. The remaining 

 elements preserved on the fragmentary skull can not be accurately determined, 

 though their probable position is indicated in plate 30, fig. 2, the lettering being 

 based on the arrangement of these elements in Capitosaurus. 



The lower jaw is poorly preserved, but what remains shows evidence of being 

 sculptured somewhat after the manner of the cranial elements. It bore strong 

 recurved teeth which are longitudinally striate. 



Measurements of the Type Specimen of Macrerpeton huxleyi Cope. 



mm. mm. 



Length of portion preserved 120 Length of jaw, as preserved 75 



Maximum width of specimen 58 Width of jaw at widest part 11 



Length of orbit 20 Length of longest tooth 8 



Width of orbit ... 1 4 Width of tooth at base 4 



