32 AMPHIBIA AND PISCES OF THE PERMIAN OF NORTH AMERICA 



Parioxys ferricolus Cope. 

 Proc. Am. Phil. Soc, vol. xvn, 1878, p. 521. 



Type: The same as the genus. 



Original description: "This salamander is represented by two crania of 

 similar size, to one of which a few vertebrae are attached. I have not yet 

 removed the matrix inclosing the latter, as it is a task requiring much time. 

 The general form of the skull is a triangle with rounded sides and narrowed 

 and obtuse apex. The parietal region is rather elevated and wide, and is 

 bounded by a low, angular ridge, which extends anteriorly from the epiotic 

 angle, diminishing in prominence to the orbit. The external border of the 

 epiotic next the auditory notch is acute, and the posterior angle is decurved, 

 as though it formed the rim of a large membranum tympani. Between the 

 epiotic cornua the supraoccipital border is concave. The middle of the 

 parietal region is concave. 



"The orbits are large and have prominent rims, which separate a concave, 

 interorbital region, which is less than half as wide as the longest (antero- 

 posterior) diameter of the orbit. The rim is most prominent at the front 

 of the orbit, anterior to which the side of the muzzle is somewhat swollen. 

 There is no canthus rostralis; in its stead there is a concavity behind the 

 nares, with an intervening swelling just behind the latter. These are equally 

 lateral and superior in their presentation. The middle of the muzzle is 

 slightly concave, with a low, median longitudinal ridge. If there be any 

 sculpture of the surface of the cranial and mandibular bones, it must be 

 slight; where the thin layer of the fine-grained matrix which invests it has 

 been removed, it is smooth. 



"The crowns of the teeth are rather slender; one from the posterior part 

 of the premaxillary bone does not display any cutting edges nor facets. 

 The grooves of inflection are strong and extend well towards the apex, but 

 they are not numerous. 



"Measurements. 



M 



"Length of skull from the muzzle to epiotic angle o. 100 



Length of skull from the muzzle to supraoccipital 090 



Length of skull from the muzzle to front of orbits 045 



Length of skull from the muzzle to nares (axial) 012 



Width of skull at extremities of quadrates 083 



Width of skull between epiotic angles 035 



Width of skull between orbits 015 



Width of skull at front of orbits 066 



Width of skull between nares 015 



Long diameter of orbit 025 " 



Fig. 4. — Parioxys ferricoUs. No. 4309-10 Am. Mus. X fi'. 

 Lateral view of skull. 



Revised description of the genus and species: This animal is represented by 

 the skull alone and was considered by Cope as a young Eryops, but there 



