AMERICAN PALEOZOIC CEPHALOPODS 
215 
belongs to the siphuncle, and no part of this cylindrical portion 
to the endocone. 
Locality Md Horizon . — Multona brook, 2 miles northeast of 
Middleville, New York; specimens No. 59449, U. S. National 
Museum. One mile above Poland, in Herkimer county. New 
York; specimen 59450, U. S. National Museum. Both localities 
in the Trenton limestone. 
14. CAMEROCERAS CALUMETTENSE SP. NOV. 
PLATE XXIV FIGS. 6A-E 
Specimen 05 mm. in length, consisting of part of a siphuncle 
traversing nine camerae in a length of 52 mm. and terminating 
at the base in an endocone three camerae in length. Possibly the 
siphuncle is one camera less and the endocone one camera more 
in length, since in two other specimens the endocone is four 
camerae in length. 
In the longer specimen here figured (PI. XXIV, Figs. 6 A, B), 
the siphuncle narrows from a width of 12 mm. immediately 
above the point of departure of the endocone to 10.5 mm., 8 
camerae farther up. A second specimen shows the same nar- 
rowing of the siphuncle in an upward direction. 
Not only the siphuncle, but also the endocone, is flattened ven- 
trally by contact with the ventral wall of the conch. This is 
indicated by 3 specimens. (Plate XXIV, Figs. 6 A, C). Except 
along this flattened ventral part, both the siphuncle and the endo- 
cone are annulated toward the interior of the conch. The lower 
margin of the septal funnels, as seen on casts of the interior of 
the siphuncle, forms an angle of 60° to 70° with the vertical axis. 
Along the greater part of its length, the annulations of the siph- 
uncle are parallel to the lines of contact with the septa, but, on 
approaching the upper margin of the endocone from above, the 
angle made by the annulations changes to 75° or 80° with the 
vertical, thus shortening the distances between the annulations 
on the dorsal side of the siphuncle. 
On the ventro-lateral sides of the siphuncle, vertical sections 
of the septa can be traced for 6 mm. from the siphuncle. Ven- 
trally, the siphuncle was in direct contact with the wall of the 
conch. 
The siphuncle appears to consist of a darker exterior layer 
and a lighter colored interior one. The darker layer evidently 
is a continuation of the septum and can be traced downward the 
