390 PALEONTOLOGY OF OHIO. 



As observed by Prof. Wyman, the genus presents some points of simi- 

 larity to the Anura. The prolongation of the angles of the mandible is 

 of this character, as well as the general form of the head. The bones of 

 the fore-arm may be united as in fr<»gs, and the length and curvature of 

 the femur are seen among these animals rather than the Salamanders. 

 The form of the femur is different from that of Amphibamus grandiceps^ 

 Cope, which also differs in the unossified condition of the vertebrae and 

 presence of dermal scales. 



Pelion Lyellii, Wyman. 



Raniceps Lyelli, Wyman, 1. c. 



The form of the head of this Batrachian is not unlike that of a frog or 

 toad ; it is as broad as long, and contracted forwards. The angles of the 

 mandibles project considerably behind the posterior margin of the cra- 

 nium, or that of the exoccipitals and parasphenoid ; the}^ present an in- 

 terior expansion. The base of the cranium behind has the form seen in 

 the frog, and is probably composed of the transverse processes of the 

 parasphenoid and the pterygoid. The latter evidently diverge towards 

 the maxillaries, in order to inclose large and posteriorly extending or- 

 bits. The mandibular rami are slender and curved, and in contrast 

 with those of Tuditanus punctulatus and others. No palatine or vomerine 

 teeth penetrate the carbonaceous layer that covers the under side of the 

 cranium. 



The vertebrae have the centra as broad as long, and medially some- 

 what contracted ; diapophyses are not defined. Across the fifth vertebra 

 a raised line extends, which may be the border of a scapula or other 

 plate ; across the ninth rests the head of the left humerus. The centra 

 are more or less defined to the thirteenth, when they disappear; beyond 

 this point there are indications of the continuation of the column, but 

 so interrupted as to induce the belief that the centra are not ossified. 

 The hind limbs are represented by the right femur and tibia. 



The fore limbs are stout, and the humeri rather elongate. The latter 

 are thickened proximally, and flattened and dilated distally. It is not 

 absolutely certain, but highly probable, that the ulna and radius are 

 proximally united, as in the Anura. The fore-arm of the left side is 

 narrowed proximally, and exjDanded and notched distally ; from the 

 notch a groove extends to the proximal end of the distal two-thirds of 

 the length. That of the right side is more expanded proximally, as 

 though a flat view of the portion seen, perhaps on edge, on the left side. 



