1877.] 193 [Cope. 
prominent ridges. The interior is hollow, and the walls are composed of 
a few concentric layers without external enamel or cementum. The solid 
base to which it is attached is shallow, presenting smooth surface on the 
opposite side, which is deeply impressed by a longitudinal groove at one 
end. 
The characters of this species are pointed out at the place above quoted. 
The measurements of a large specimen are: length .015 ; diameter of base, 
long .008 ; short .005. 
I am not sure as to the part of the skeleton to which this body should be 
referred. 
CLEPSYDROPS LIMBATUS sp. nov. 
The discovery of a species of the genus Clepsydrops in Texas, in a forma- 
tion hitherto regarded as Triassic, adds weignt to the view above expiessed, 
that the Clepsydrops shales of Illinois belong either to the Triassic or Per- 
mian formations. As typical of the new species I select a vertebra, which 
may be exactly compared with corresponding one of (@. collettit. The 
centrum is about as wide as long, and its sides are very concave, much 
more so than in C. colletti?7, and the rim-like borders of the articular ex- 
tremities are connected by a straight compressed hypopophysial keel. The 
sides of the foramen chord dorsalis are convex in the longitudinal sec- 
tion, thus contracting the opening, as compared with the very wide flare of 
the border of one of the extremities of the centrum. This flare receives 
the wide recurved border of the opposite extremity of the adjoining cen- 
trum, forming a kind of ball and socket articulation. This reflected sur- 
face forms a ridge with the funnel of the foramen at this extremity of the 
vertebra. The concave extremity is produced downwards, so that the for- 
amen is considerably above the middle point. The diapophysis and para- 
pophysis are not distinct nor elongate, but are represented by a projecting 
scar on the superior part of the centrum, which is directed downwards and 
forwards towards the rim of the articular face. 
Besides the great contraction of the centrum, its relatively shorter form 
distinguishes it from that of C. collettid?. It is also much larger than that 
species and the C. pedunculatus, being the largest of the genus. 
Measurements. M. 
Meno fs oniCemtrwiMns aerate iie.c siessle.eiseeis cies tee caris reste) COOL 
: (Gvertical pi. scoomonsopocooen ~AUBI 
Diameter of centrum ; tTAHSVErSesR ee eR eee asses LOSS 
Whaidthtotencurilecamalien 4 So:4 sci.cienisade a ascites faci. «006 
Discovered by: Jacob Boll. 
On Reptilian remains from the Dakota Beds of Colorado. 
By E. D. Corr. 
(Meeting of American Philosophical Society, November 2, 1877.) 
Since the discovery of the huge saurian Coumarasaurus supremus (Cope, 
Paleontological Bulletin, No. 25, p. 5), Superintendent Lucas has explored 
PROC. AMER. PHILOS. SOc. xviT. 100. Y. PRINTED JAN. 9, 1878. 
