96 PSEUDOCERATITES OF THE CRETACEOUS. 
the sutures have to be perfect to see this clearly. The third is about 
one-half the length of the second, and from this one the decrease in length 
is gradual to the lines of involution. The third, fourth, and fifth lateral 
lobes are broader in proportion and correlate with the forms of the 
accompanying saddles. There are eight lobes and nine saddles on the 
oldest parts of this volution, the seventh lobe bemg on the umbilical 
shoulder. 
The septa are concave along the median plane, being convex only at 
the ventral and antisiphonal lobes. The large third saddles, the first of 
the auxiliary series, correspond to the first pair of dorsals and are connected 
with them so that the number of saddles on the dorsum is the same as the 
number of lateral saddles, or six, exclusive of the saddle on the line of 
involution. The details of their curves could not be seen. 
Locality: Near Carthage, N. Mex. 
Age: Colorado group, Upper Cretaceous. 
CorLoPpocERAS SPRINGERI n. sp. Hyatt. 
This superb specimen, presented to the Museum of Comparative 
Zoology by Frank Springer, of Las Vegas, the well-known student of 
crinoids, appears to have characters so distinet that they can not be 
accounted for by the extreme size and age of this specimen. it is 400 
mm. in diameter. The last part of outer volution from lines of involution 
to venter, which is slightly truncated by abrasion, is 225 mm., and half of 
a volution younger it is 196 mm. This, judging from thickness of the shell 
on younger part (5 mm.) and siphunele at this part 7 mm. in diameter, has 
lost 12 to 15 mm., and to this must be added shell in the umbilicus, which 
was 5mm. At the last part of the second quarter of this volution, where 
sutures were studied, the volution was 195 mm. in breadth; the allowance 
of 5 mm. for shell on venter and of 3 mm. for shell in umbilicus makes the 
volution when complete 203 mm. The actual measure of same diameter 
near beginning of first quarter, which was entirely covered by shell, was 
149 mm. The inner layer of the shell was not present in umbilicus and 
probably added 2 mm. to this measurement. 
There is only a small part of the living chamber left on this large 
