1878.] 521 [Cope. 
ing the maxillaries in size within the latter, perhaps on the palatine bone. 
No row of smaller teeth within the maxillary series, or on the vomer, as in 
Mastodonsaurus and Capitosauras. The choane are large, and extend 
well forwards. 
This species is the most abundant as well as the largest Batrachian of the 
formation. Some of the crania are .500 Ms. in length. 
It may be added that the vertebre which I described (1. c.) under the 
head of this species, and which were found with the cranium which repre- 
sents it, may not really belong to it. 
PARIOXYS FERRICOLUs. Gen. et sp. nov. 
Char. Genericus. Suborder Labyrinthodontia. Head of medium pro- 
portions, with orbits near the middle of the length, and lateral external 
nares. Epiotic bones prominent, bounding a deep auditory notch. Mandib- 
ular angle projecting beyond the glenioid cavity. Maxillary and premax- 
illary teeth not large, conic, subequal; within them a series of rather 
numerous teeth, of near the same size, probably rising from the palatine 
bone. No lyra discoverable. 
This genus resembles Rhinosaurus and Eryops, but belongs to the 
group with prolonged mandibular angle. Among these it differs from 
Mastodonsaurus and its immediate allies in the deep auditory notch and 
prominent epiotic bones. From Labyrinthodon and Anthrucosaurus, the 
uniform sizes of its teeth distinguish it; while there is no indication of 
the facial fontanelle of Dasyceps, which is otherwise much like Pariozys. 
Char. Specif. This salamander is represented by two crania of similar 
size, to one of which a few vertebrie are attached. I have not yet removed 
the matrix enclosing the latter, as it isa task requiring much time. The 
general form of the skullis a triangle with rounded sides and narrowed and 
obtuse apex. The parietal region is rather elevated and wide, and is bounded 
laterally by a low, angular ridge which extends anteriorly from the epiotic 
angle, diminishing in prominence to the orbit. The external border of the 
epivtic next the auditory notch is acute, and the posterior angle is de- 
curved, as though it formed the rim of a large membranum tympani. Be- 
tween 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 mediau 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 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 
PROC. AMER. PHILOS. SOc. XVII. 101. 3M. PRINTED MAY 17, 1878. 
