Cope.] 54 {May 20, 
direction, and the other two in the other.- Between the last of the latter 
and the inner border is a rudiment of another in the form a rugosity. 
None of the crests touch each other at their bases. At their extremities 
they curve rather abruptly downward, and do not project beyond the in- 
ferior plane, from which each one is separated by a deep fossa, whose 
mouth is a notch in its base. The crests are coarsely dentate, there being 
three or four teeth on each, and the grooves between them are marked by 
coarse transverse undulating grooves. The inner border is a deep vertical 
plane ; the inferior face is narrow and concave in transverse section. 
Motel Meret hye. accictice ied doviaws oon saen ee maeesae seen cee eace eed aocees mee 
Greatest width........... aa #) Waite sebisacrleatls Secateoe Se des steenastetele ae OOM 
Deptheat mid dle ct cscssssssessenwececetierteces uectece tee setae . .006 
This is the first species of this carboniferous genus found at this locality. 
It differs from the C. serratus Newberry in its narrow form, small number 
of ridges, and the very slight prolongation of their extremities. 
CTENODUS GURLEYANUS Cope, sp. nov. 
This species is indicated by a portion of a tooth, which leaves the number 
of the ridges a matter of uncertainty. On this account its description might 
have been postponed, but that the distinctness of its characters, render it 
clear that it cannot be placed with any of the other species. The crown, 
as in Ceratodus paucicristatus, is narrow and rather thick ; but three crests 
are present, all radiating in the same general direction, the longer close to 
the inner border. There was not more than one additional crest, or one 
and a rudiment, and these have probably the same direction as those which 
are preserved. The crests are sharp, elevated, and coarsely dentate ; they 
are not decurved at the extremity, but cease abruptly with a projecting 
denticle, beneath which the basis is excavated by a shallow fossa. The 
inferior face is slightly concave, the internal wall vertical. 
Greatest wwaditliyie ny oriole cioelertoichleteeieiots tekken tiem US 
Depthvatunmer orderns sc -\-ras\cvelisleieie se cei teeeisilerei ne OO ORE 
This Clenodus is dedicated to William Gurley, to whose efforts science is 
indebted for this and several other interesting paleontological studies. 
CROSSOPTERYGIA. 
PEPLORHINA ARCTATA sp. nov. 
Based on an unsymmetrical bone, bearing teeth, to be referred to the 
position of pharyngeal, pterygoid, palatine, or half of the vomerine ele- 
ments. From the resemblance of the teeth to those on the palate of Pep- 
lorhina anthracina, 1 refer it provisionally to the corresponding position in 
‘the mouth of a second species of that genus. This course is open to modi- 
fication should subsequent investigation require it. 
The bone is plate-like and diamond-shaped, with the longer angles both 
recurved. The convex surface is thickly studded with teeth, which are 
not in contact with each other. Their size increases from one side of the 
