dall] new species of shells 145 



In the regularity and extension of the ribs, the curious coloration 

 of the under layer of the shell, and the keeled siphonal fasciole, this 

 species is unique. All the specimens are decorticated hermit-crab 

 shells, but the species cannot fail to be recognized if found. 



BUCCINUM POLIUM Dall, n. sp. 



Shell of moderate size, solid, elongate-ovate, subacute, with sharply 

 constricted suture and about six rounded whorls ; nucleus eroded ; 

 whorls in front of the suture slightly shouldered, strongly axially 

 plicate ; on the spire the plicae form rounded arcuate ribs extending 

 from suture to suture, with about equal interspaces ; on the last 

 whorl there are 20 to 22, which mostly become obsolete at or a little 

 in front of the periphery ; spiral sculpture of fine, feeble, flattish 

 threads separated by narrow grooves, the threads becoming wider 

 and a little more prominent on the base and canal ; the whole is 

 covered with a pale olivaceous gray periostracum, which along the 

 incremental lines, when fresh, is delicately fringed, giving a pubes- 

 cent aspect to the shell ; aperture wholly bluish white, the outer lip 

 slightly thickened and reflected; body with a polished white callus, 

 which also extends along the inner side of the straight pillar; aper- 

 ture longer than wide ; canal short, deep, forming a well-marked 

 fasciole. Lon. of shell, 42 ; of last whorl, 33 ; of aperture, 25 ; maxi- 

 mum diameter of shell, 22; of aperture, 11 mm. Operculum with a 

 subcentral nucleus. 



Stations 501 1 and 5013, in Aniwa Bay, Sakhalin Island, in 42 and 

 43 fathoms, September, 1906. U. S. Xat. Mus., 110,523, 110,524. 



This has some resemblance to B. tenue Gray, but has a different 

 color and pubescent surface ; the ribs are larger and less irregular 

 than in tenue and the shell is more solid. 



BUCCINUM CEDEMATUM Dall, n. sp. 



Shell rather thin, swollen, short-conic, with a greenish gray 

 periostracum, which is smooth and caducous, whorls about seven,, 

 usually more or less eroded, with a chalky white substratum ; sculp- 

 ture of (on the penultimate whorl about forty) narrow, sharpish, 

 sigmoid wrinkles, with wider interspaces, obsolete on the base, 

 sparser on the last whorl, and more or less irregular, the whole sur- 

 face finely, evenly, spirally striated ; suture distinct, not deep ; aper- 

 ture milk-white, wide, ample, the outer lip deeply flexuous behind, 

 slightly thickened, and reflected; body with a wash of glossy white 

 callus ; pillar very short, obliquely truncate, moderately callous ; 

 canal wide, very short, sharply recurved, with a well-marked fas- 



