4 THE NAUTILUS. 
will immediately coil itself up again. This cylinder is of subequal 
diameter throughout, and is as long as, and somewhat stouter than, 
the cephalic tentacles. Externally, near its base, it is nearly smooth s 
further out, it is spirally striate; near its extremity, it becomes 
thicker and rather deeply externally grooved longitudinally, with 
short, even, close-set, slightly spiral, grooves. The opening at the 
distal end is fringed with short, equal papillee, each one corresponding 
to the thickened interspace between two of the grooves. These raised 
folds, or interspaces, are also finely transversely striate. At the 
base of the cylinder, the epipodium extends backward to the first 
lateral filament; and the margin of this part is perfectly entire and 
simple, showing neither fringe nor granulation. The object of this 
apparatus is self-evident. The cylinder serves as a conduit for the 
seminal fluid ejected from the verge. Whether it may be employed 
in an actual copulation is doubtful ; it may merely serve to spread 
the seminal matter over the eggs as they are deposited by the female. 
I am not aware that anything of this sort has been observed in any 
other gastropod, up to the present time. 
The edge of the mantle is smooth, entire, and slightly thickened. 
Within the nuchal chamber the anus is visible on the right side. 
The end of the intestine, for a considerable distance, is free from the 
mantle and projects like a tentacle. The termination is slightly con- 
stricted, then enlarged into a cup, or trumpet-shaped ending, which 
nearly reaches the mantle-edge. 
The intestine itself, after leaving the stomach, is much convoluted, 
but in the main, rises and is brought forward nearly to the mantle- 
edge above the stomach; then turns back and is carried far into the 
visceral coil before it is again brought forward and terminated as 
above described. The food consists of Foraminifera. 
The gill is free, except at its base, and consists of very elongate- 
triangular foundation, from which depend triangular lamelle, 
without a raphe and wide at their bases. These grow larger prox- 
imally. 
The operculum is thin, polished, amber-colored, centrally de- 
pressed, having a central projection, or nipple, on its under-side, and 
consists of about four whorls. 
. The specimen affording the above notes has been identified with 
Mr. Watson’s type specimen, and is now deposited with it in the 
British Museum. It was dredged by the U.S. Fish Commission 
east of Chesapeake Bay, in 1685 fathoms. 
