282 AIR-BREATHERS OF THE COAL PERIOD. 



pointed, and with spiral furrows at the point. Number of teeth 

 about forty on each side of jaw ; length of lower jaw about 1 inch. 

 Size more than twice that of H. Lyelli. Dermal covering so far 

 as known, similar, but the parts large in proportion. 



3. Hylonomus Wymani, Dawson. — Teeth obtusely conical, about 

 twenty in each side of the jaw ; length of lower jaw about .25 

 inch. Vertebrse elongated; size much smaller than that of H> 

 Lyelli. Bony scales small and rounded, body above probably 

 clothed in imbricated horny scales. 



Order. — Lab yrinthodontia. 



Genus. — Baphetes. 



Baphetes planiceps, Owen. — Teeth conical, hooked, striated 

 longitudinally, and with inflected and convoluted cement ; in two 

 series; the inner of larger size. Cranial bones much corrugated. 

 Head broad ; breadth in front of orbits 6 inches ; length from 

 this line to front of snout 3j inches. Probably a dermal covering 

 of corrugated bony scales. 



Genus. — Dendrerpeton. 



Batrachians with a double series of teeth ; the outer simple and 

 flattened conic, the inner conical with inflected folds of cement* 

 Teeth also on the vomer. Bones of skull corrugated ; body pro- 

 tected below with long ovate or rhomboid bony scales, and above 

 with imbricated horny scales. Form elongated, fore limbs largest, 

 tail natatory, vertebrae biconcave, neural arches and bodies 

 ossified. 



1. Dendrerpeton Acadianum, Owen. — Inner teeth straight, 

 conical ; outer teeth short and obtuse. Length of head 2.75 inches, 

 breadth at orbits about 2 inches, distance of orbits .7 inch„ 

 Length one to two feet. 



2. D. Oweni, Dawson. — Teeth slender and hooked, and cement- 

 of inner teeth more perfectly inflected. Length of skull 1.2 inch, 

 distance of orbits about .5 inch ; length one foot or less. 



Order. — Archegosauria ? 



Genus. — Hylerpeton. 



Hylerpeton Dawsoni. — Owen. — Teeth simple, bluntly conical, 

 with large pulp cavity ; about 13 in one side of the jaw. Two 

 of the anterior teeth of the upper jaw twice as large as the others. 



