AMERICAN PALEOZOIC CEPHALOPODS 
213 
13. CAMEROCERAS TRENTONENSE CONRAD 
PLATE XXIV, FIGS. 1-5 
Cameroceras tren'tonense Conrad, Jour. Acad. Nat. Sci. Philadelphia, 
vol. 8, 1842, p. 267, pi. 16, fig. 3; Hall, Pal. New York, vol. 1, 1847, 
p. 221, pi. 56, figs. 4a-c 
Specimens figured by — Both specimens are compressed 
laterally, and in each there is a tendency toward angularity on 
the dorsal or antisiphonal side of the conch. The dorso-ventral 
diameter of the shorter specimen is 24 mm., and the lateral 
diameter is 21 mm. Viewed from the ventral side the conch 
looks slightly broader than when viewed from the dorsal side. 
The rate of enlargement of the conch evidently was small. The 
dorso-ventral diameter of the longer specimen is 26 mm. and 
the lateral diameter is 19 mm. It is possible that this lateral 
compression is due to pressure during fossilization. 
The number of camerae in a length equal to the dorso-ventral 
diameter of the conch is from three to three and a half. The 
sutures of the septa curve slightly downward laterally, forming 
shallow lateral lobes and very low dorsal and ventral saddles; 
this is another feature which probably is not constant in the 
species. The septa curve in a dorso-ventral direction with a 
radius of 14 mm., and laterally with a radius of 8 mm., again 
suggesting lateral pressure. The siphuncle is in contact with the 
ventral wall of the conch for a width of 3 or 4 mm., so that this 
side of the siphuncle does not show the annulations which cross 
the remainder of the siphuncle obliquely. 
In the longer specimen, the conch is straight ; the exposed part 
of the siphuncle is likewise straight; the bend at the junction of 
the siphuncle with a remainder of the conch evidently is due to 
distortion during fossilization. In the shorter specimen, the 
septal necks contract within the upper half of the camerae, ex- 
pand within the lower half, and then contract again toward their 
lower margin, so as to admit of the insertion of this margin into 
the top of the next lower septal neck. The surface of the conch 
apparently is smooth. 
Locality and Horizon. — Middleville, New York; in the Tren- 
ton limestone. 
Specimens No. 815, American Museum of Natural History. 
Multona Brook and Poland specimens. — Cross-section of conch 
This Journal, pi. 24, figs. 1, 2. 
