164 PSEUDOCERATITES OF THE CRETACEOUS. 
The fragments from Denison consist of an almost entire gerontic living 
chamber and one somewhat more imperfect one of the same age, a smaller 
fragment of part of ephebic living chamber and last suture. This last 
shows that in the ephebic stage the venter is smooth, narrow, concave, and 
has no tubercles, but is bordered by two smooth ridges. There are nine 
lobes and nine saddles, the seventh and eighth saddles being bifid. The line 
of involution is occupied by a minute lobe, as it is also in other specimens. 
There are five dorsal lobes between this and the antisiphonal lobe on each 
side. he first dorsal saddle next the antisiphonal is entire, the second and 
fifth are bifid, the rest are entire. The third dorsal lobe was bifid, the 
remainder on both sides of this were entire and narrower. The antisiphonal 
lobe was narrow and bifid. The sutures of an early ephebic or late neanic 
substage in one of these showed that the notation of the saddles in this 
group is correct, and that the first lateral has, as stated, two unequal arms, 
the inner being really an adventitious saddle derived from the imner side 
of the first lateral. The outer saddles and lobes are similar in outline to 
those of some specimens from northeast of Gainesville, but the inner saddles 
and lobes are shorter and broader.. : 
A specimen from Denison, kindly lent me by Prof. F. W. Cragin [is 
also figured and is probably one of the types of his variety serpentinus now 
raised to specific rank]. 
This species is distinguishable from others by the extremely late stage 
to which the protengonoceran venter—i. e., the concave venter bordered by 
two ridges—is retained. Practically it lasts throughout the ephebic stage, 
and the engonoceran stage is passed through with great rapidity. In this 
the venter is flat and bordered by weli-defined elongated tubercles, and 
consequently there is a quick appearance of the senile stage with elevated 
convex venter between large elongated nodes. It should be noticed that 
one of the varieties imitates the sutures of EH. subjectum in the shape of the 
saddles and lobes, but these remain characteristically simple in outline 
(Pl. XIX, fig. 11). Some varieties have bifid saddles and some do not have 
them. The dividing marginals of the saddles enlarge by growth when they 
occur, until they often form lobes practically inseparable from others. 
Locality: Four and one-half miles northeast of Gainesville and 
Denison, Tex. 
Age: Upper part of Comanche series, Paw Paw beds, Washita group. 
