^8 The American Geologist. January, i905 
them. They are very similar to the septal rings of the siph- 
imcle of Piloceras and each of them is curved concavely and 
shallowly backward on the convex inner side, and forward, 
into a narrowly rounded, short, tongue-like process, on the 
flattened peripheral side. 
Longitudinal sections of the praeseptal cone show very 
little if any structure. But, in similar sections, the pro- 
ionged portion of the siphuncle is seen to be filled with 
numerous and closely disposed, invaginated sheaths, and the 
endosiphuncle to open anteriorly into a large and deep fun- 
nel-shaped cavity, as represented in figure 4. In a specimen 
in which parts of the sutures of some of the septa are pre- 
served, the sutural lines are closely approximated and about 
three or four millimetres apart. 
External test unknown. 
Railway cutting at Kingston Alills, near Kings,ton, Ont., 
Dr. R. W. Ells, W. A. Johnston, and J. F. Whiteaves, 1902: 
•several imperfect casts of the interior of the siphuncle, and 
one specimen with parts of the sutures of some of the septa 
preserved. These casts are broken in all directions, longi- 
tudinally and transversely, and their broken ends are some- 
times worn and rounded, in the matrix, evidently prior to 
their fossihzation, but the septal rings are often remarkably 
well defined. The best specimens are pieces of the Nanno- 
like apical end, from a little over an inch to fully two inches 
in length, and of the subsequent prolonged or longicone por- 
tion, from two to four and a half inches in length, but in no 
•cases have the two been found united. 
The exact age of the limestone at Kingston Mills, in 
which these siphuncles occur, is still uncertain. 
On page 178 of the Geology of Canada for 1863, it is 
stated that "at Kingston Mills an exposure of twelve feet in 
thickness, of much the same character as the lower portion 
of the strata" between the Potsdam sandstone and the 
Birdseye and Black River formation, "is seen resting on 
gneiss, in the excavation made for the Grand Trunk Rail- 
way. In this a fossil occurs, somewhat resembling the siph- 
uncle of Piloceras canadetise, but it may be a fragment of 
