I 



THE NAUTILUS. 3 



The oral disk is entire, but is sliglitly indented in tlie median Vnw. 

 below a furrow running up toward the mouth. 



The cephalic tentacles are very stout and large, very elongate- 

 conical, with moderately pointed tips. They are situated above, and 

 not, as in most Trochidce, on each side of the muzzle. Their inner 

 bases are connate, and there is no intertentacular "veil," or any 

 tubercular traces thereof. 



The eyes are large, strongly pigmented, ovoid, and sessile on the 

 outer bases of the tentacles, or ])erhaps T should say, just by the outer 

 bases. They are not pedunculate or elevated on pedicels in any of 

 the specimens examined, and 1 am quite confident that this is not 

 caused by the contraction due to alcohol, but is normal to the sj)ecies. 



The epii)odial apparatus is complicated, and exhibits a certain 

 amount of variation between diffei-ent individuals in the situation 

 and number of its processes. In the males, it is subjected to a re- 

 markable modification for sexual purposes. The epipodium begins 

 immediately behind the eye and a trifle below it. In the females it 

 is produced into a large broadly linguiform process, half as long as 

 the cephalic tentacles and fringed with close-set uniform small pointed 

 papillae or filaments. This process exists in the male on the left side. 

 The posterior margin then curves in toward the side of the foot ; it 

 becomes quite narrow and shows two lateral tentacles of moderate 

 size; then a vacant space ; then at the front edge of the operculum 

 two or three filaments, small, but larger than any in the vacant 

 sjiace ; then another, but larger one ; and finally another, which is 

 behind the middle of the operculum, and is the last on that side. 

 The e})ipodial line is continued to the end of the foot, the dorsal sur- 

 face above it, being transvei*sely rugose and with a linear median 

 furrow. On the other (right) side we find a small, a large, two sub- 

 equal small, another large filament, followed by a slight gap and 

 then by a still larger tentacular process. The flap which corresponds 

 to the fringed process on the left side, is remarkably modified in 

 the male. 



Behind, and close to the right eye, is a small tubular, longitudi- 

 nally striate, cylindrical verge, not exceeding (in alcohol) two mill- 

 imetres in length. Below it the epipodial flap is enormously pro- 

 duced, and its front edge is rolled backward upon itself, forming a 

 tube into the proximal opening of which the end of the verge may 

 project. The fla]) is rolled so that it makes nearly two layers, and 

 thus a verv capable cylinder, which, when unrolled and released, 



