332 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



Hipponix serrata Carpenter. 

 Hipponyx serratus Carpenter, Maz. Cat., 1856, p. 296. 



U. S. S. " Albatross," station 2798, in Panama Bay, in 18 fathoms, Mazat- 

 lan, Reigen. U. S. N. Mus. 110,654. 



Naticidae. 



NATICA ScoPOLi. 



Natica Scopoli, Intr. Hist. Nat., 1777, p. 392 (after Adanson) ; type, N. vtttllus 

 (Linne) ; Lamarck, Prodr., 1799, p. 77; Bole ex., N. canrena Linne'. 



The forms with calcareous opercula having been indicated by Lamarck as typi- 

 cal, we may, as I have indicated in my Report on the Oregon Miocene, subdivide 

 the group in part as follows : 



Natica s. 8. Umbilicus open, with a spiral ridge internally ; operculum externally 

 spirally multisulcate. N. vitellus Linne. 



Cochlis Bolten, 1798. Umbilicus similar to that of Nnticn s. s. Operculum with a 

 very few, or only a single marginal sulcus. ^V. spadicea Gmelin. 



Cryptonatica Dall, 1892. Operculum smooth, without spiral sulci, umbilicus com- 

 pletely closed with a smooth pad of callus. N. clausa Brod. and Sowerby. 



The first and second groups are tropical or subtropical ; the last is cool-temper- 

 ate or arctic. There are several other groups, such as Nacca, Stigmaulax, and 

 Payreaudeautia, but these are not represented in the present collection. 



Natica (Cochlis) othello Dall, n. ep. 



Shell rather thin, elevated, with a rather pointed spire of four and a half whorls 

 of which four are nuclear, smootli, and brownish, tlie remainder buff, very pale 

 brown, or grayish-wliite, with a polished surface ; suture very distinct, not chan- 

 nelled or appressed ; periostracum dehiscent, cliaffy, pale yellowish-brown ; an 

 obscurely defined whitish band in front of the suture and at the base ; axial sculp- 

 ture of sharply incised, numerous retractive lines, forming a halo in front of the 

 suture and behind the shoulder of the whorl ; there are about two or three of 

 these radii to the millimeter and they average about four millimeters long on the 

 last whorl, with wider, radially striated interspaces ; the remainder of the whorl is 

 smooth, except for faint increnientnl lines, and more or less obscure, obsolete, 

 spiral striation; umbilicus narrow, with a nearly vertical, strong spiral internal 

 rib, nearer the anterior wall of the umbilicus; aperture oval, outer lip sharp, thin ; 

 body with a moderate white callus, interrupted in front by the umbilicus ; pillar 

 white, throat livid flesh-color; operculum shelly, of two and a half whorls, inter- 

 nally smooth and slightly convex, externally flattish, apically depressed, white, with 



