V0 1889 XI1 '] PROCEEDINGS OF THE NATIONAL MUSEUM. 323 



iu the previous species, the females being generally somewhat more ro- 

 bust and having the concave wave in the outer lip somewhat more pro- 

 nounced. The operculum of the extremely young is buccinoid, but 

 this character is lost very early. Perhaps this may be found to be 

 the case throughout the genus. 



Chrysodomus aphelus sp. nov. 



Plate vi, Fig. 7. 



Shell small, bucciuiform, six whorled, smooth, covered with a green- 

 ish-gray epidermis; nucleus minute, eroded; whorls full, well rounded: 

 suture distinct, not deep nor channeled; sculpture only of taint incre- 

 mental lines and a few obscure spiral traces; aperture moderate, the 

 outer lip thin, very slightly reflected, flexuous; body and pillar lips 

 white, polished, without callus; pillar short, strong, curved, obliquely 

 truncate anteriorly, well recurved; canal short, wide, well defined, and 

 recurved; throat smooth, white; axis not pervious; operculum normal. 

 Maximum longitude of shell, 30; maximum latitude, 15 mm . 



11 ab. — Station 2839, in 414 fathoms, off the coast of Santa Barbara 

 county, California. 



The soft parts of this species agree with those of the preceding, C. 

 griseus, except that iu the sole male specimen a blunt papilla protrudes 

 from the oval depressed area at the end of the verge, and a little more 

 than one-fourth the way from the external bases of the tentacles to- 

 ward their tips are situated eyes of unusual size and blackness. The 

 dentition does not differ from that of C. griseus. Here we have the in- 

 teresting fact of two species of the same group, nearly related, from 

 the same identical spot in the archibenthal region of the Pacific, in one 

 of which the environment has induced blindness, while in the other the 

 eyes have been retained and become larger, and in all probability more 

 sensitive. This seems to me to indicate the existence of a certain 

 amount of light on the sea bottom at over 400 fathoms.- 



This modest little shell presents few salient characters, but its very 

 simplicity is notable and attractive. With the preceding species it 

 belongs to a peculiarly bucciuiform group, which are characterized by 

 a strongly reflected lip, short canal, and minute nucleus in the shell, 

 but which, so far as the soft parts are concerned, present no obvious 

 points of difference having systematic value from the larger and, so 

 far as the shell is concerned, more normal species from shallow water. 



Subgenus SIPHO Morch. 

 Chrysodomus (Sipho) Rushii Dull. 

 Plate v. Fig. 1. 

 Clmjsodomus (Sipho) Rushii Dull. Bull. Mus. Conip. Zool., win, p. IT.".. June, 1889 



.Shell small, thin, white, elongated, with a furfurescent epidermis and 

 six- whorls. Nucleus regular, white, smooth, but becoming gradually 



