Sf 
254 WB. Dwight—Fossils of the Wappinger Valley. 
& 
cephalic shield not thoroughly defined in the specimens. Tho- 
rax and pygidium unknown. : 
Locality—Calciferous. Ledge D, Rochdale, N. Y.  Frag- 
ments of half a dozen individuals found. 
CEPHALOPODA. 
Cyrtoceras Vassarina, n. sp. 
Fi nd 8. 
_ Shell stout, large and smooth, varying in the same individual 
rom 1™ to 2™" in thickness; considerably curved in most 
specimens ; the transverse-section is more or less distorted by 
one-fifth shorter than-the dorso-ventral axis. Taper gradual, 
about one part to nine near the chamber of habitation. 
ta from 10 to 15 or more to the inch, deeply concave, the 
‘concavity exceeding by one-half the depth of the interseptal 
spaces; their marginal sutures but slightly curved along the 
lateral margins, arching somewhat forward toward the concave 
ventral margin, and very strongly forward toward the convex 
dorsal margin. The extent of this forward deflection near the 
dorsal and siphuncular side, about equals three of the inter: — 
septal spaces, while that near the ventral side is somewhat less — 
than one interseptal space. In several of the most marked 
specimens, the line joining in a cross-section, the points of max!l- — 
mum deflection to the front, on the opposite margins (shown DY 
the dotted line in fig. 7a), would show a considerable angular 
deviation from the dorso-ventral line. 
iphunele marginal, somewhat flattened, and of moderate 
proportional size, which is probably somewhat variable in dif- 
ferent individuals of the species. In the specimen described 
The chamber of habitation is capacious. Locality —Oaleif 
especially at Ledge D. 
