128 



BATRACHIA. 



France. The head is short and broad with relatively large orbits, and all 

 the elements are clearly distinguishable. No teeth have been noticed on 

 the palate, except perhaps on the vomers. The normal ring of sclerotic 

 plates is supplemented above by an extensive covering of smaller and 

 more irregular plates evidently developed in the s^ame tissue. The pre- 

 sacral vertebrae are about 26, the ossified caudals about 15 in number. 



D. 



FIG. 84. 



Diagrams of Pectoral Arch of Stegocephalia, ventral aspect. A. Branchiosaurus, 

 three times nat. size. B. Pelosaurus, twice nat. size. c. Discosaurus, twice 

 nat. size. D. Hyloplesion, twice nat. size. E. Archegosaurus, about one- 

 quarter nat. size, c, coracoid (scapula of Gegenbaur) ; cl., clavicle ; 

 e, interclavicle ; s, calcined tessera in cartilage ; sc., scapula (cleithrum of 

 Gegenbaur). (After Credner.) 



Impressions of the soft tissues on the Lower Permian coal-shale of 

 Niirschan (Nyran), Bohemia, show that the tail was about as long as the 

 trunk with the head, most of the caudal vertebrae remaining unossified 

 and thus not observable in the fossils. The ribs are longest in the 

 thoracic region and gradually become insignificant immediately in front 

 of the much-enlarged single pair of sacral ribs, which, like all the others, 

 are merely articulated (not fused) with the vertebral transverse processes. 



