Cope. I J-OO TNov. 2, 



large for the animal to which the vertebra pertained, but the proportion is 

 not different from that which I describe below in the genus Eryops. 



The surface of the centrum is smooth and is without grooves. The 

 diapophyses and parapoyhyses are rather elongate, and are closely approx- 

 imated one above the other. The superior process issues from the centrum 

 opposite the superior margin of the articular faces. They stand equidis- 

 tant from the extremities of the centrum, and are directed obliquely back- 

 wards. The anterior zygapophyses occupy the same level. The neural 

 spine is a compressed longitudinal ridge ; it divides behind, leaving a notch 

 between the posterior zygapophyses. 



Measurement*. M 



Hongitudinal 0060 



Diameter of centrum -<j vertical 0025 



( transverse 0025 



Depth of centrum and neural arch ... 0060 



"Width with transverse processes 0070 



Expanse of posterior zygapophyses 0050 



The mandibular ramus which accompanied one of the vertebrae is shal- 

 low and stout. Its external surface is sculptured with sharp longitudinal 

 ridges, which inosculate more or less. The teeth have cylindric roots 

 which occupy shallow alveoli sunk in a plane surface. The crowns are 

 rather elongate and compressed near the apex, and without grooves or 

 serrse. In contact with the jaw is an osseous fragment with a pitted or 

 reticulated surface. 



Depth of ramus 0030 



Length of crown of tooth ..:..; 0023 



Four teeth in 0040 



Eryops megacephalus Cope gen. et. sp. nov. 



Char. gen. The details of the structure of this genus are derived 

 from an almost entire cranium with underjaw, which is accompanied 

 by numerous vertebrae and other bones. The form is Labyrinthodont, and 

 embraces the largest species of that group yet known from this continent. 



The skull is not elongate, and the quadrate bones are produced far 

 backwards. The epiotic processes are present but not remarkably elon- 

 gate. The temporal fossa is covered in by the usual roof. The orbits are 

 round, posterior in position, and small. There is no postorbital depression 

 or groove, and the lateral epiotic sinus is not deep. The nostrils are large 

 and widely separated. There is no angular process of the mandible. The 

 maxillary teeth are of different sizes, although arranged in a single row. 

 The posterior are small and not closely placed ; large teeth appear anterior 

 to the middle. "The premaxillary bone supports a number of large teeth. 

 Those of the mandible which are visible in the specimen in its present, 

 state, those opposite the nares, are of medium size. The form of the 

 crowns of the teeth is conic, with weak fore and aft cutting edges. There 



