382 



PALEONTOLOGY OF OHIO. 



dilated distally ; the coracoid slightly dilated at its superior extremity. 

 The dermal armature commences immediately behind the head, and 

 forms a band of fourteen lines in width ; measuring across the spine-like 

 scales, in a width of a line, four cylinders may be counted. The ex- 

 ternal portions are curved backwards, the interior nearly straight, those 

 of the anterior series more delicate than the posterior. 



The head is wedge-shaped, with regularly converging sides. The top 

 of the cranium is somewhat broken in the specimen ; the portions pre- 

 served are smooth, and the longitudinal suture is distinct for a consider- 

 able distance. The angle of the mandible is produced considerably 

 behind the occiput, and is enlarged and rounded. The end of the muz- 

 zle is broken away, and the region of the orbits so fractured as to render 

 their precise location uncertain. The superficial layer of the cranial 

 bones is nowhere clearly visible, so that it can not be ascertained 

 whether it is sculptured or not. The quadrate bone projects well poste- 

 riorly. Some fragments indicate small cylindric teeth, as in Amphiba- 

 mus, but they are not characteristic. 



Length of cranium without muzzle, 17.3 lines ; width do. posteriorly, 

 11.6; length of the first haemal branchial, 2.1; length second do., 2.5; 

 length of sixth vertebra from skull, 3 ; extent diapophyses, 3.5 ; width 

 centrum, 1.5. 



The characters of the genus are further shown by a part of another in- 

 dividual in the same coal slate matrix. The cranium and anterior por- 

 tion of the vertebral column only are preserved, the latter so much in- 

 jured as to render the vertebral characters very obscure. As in the 

 other, the bristle-like scales extend along the ventral region to near the 

 cranium. The anterior two-fifths of the ventral side shows a large num- 

 ber of oval scale-like bodies, which belonged undoubtedly to the animal, 

 and were probably dermal scales. They are, however, neither regular in 

 form nor position. Close behind the head two or three long bones of the 

 branchial arches have been exposed. They are slender and similar to 

 those of the last specimen. 



The cranium, though without the apex of the muzzle, shows its long 

 wedge shape. The maxillary bone can not be distinguished, nor can the 

 orbits be made out. One ramus mandibuli is pretty well preserved; it 

 shows no coronoid process. Thirty-one teeth may be counted on a por- 

 tion a little more than one-third its length. The anterior eleven of 

 these are longer and stouter than the others. They are all, except a few 

 most anterior, in pairs, i. e., with a slight vacancy between every two. 



