58 PROCEEDINGS OF THE NITTOXAL MUSEUM. vol.49. 



RISSOINA NEWCOMBEI Dall. 



Plate 33, fig. 7. 



Rissoina newcomhei Dall, Bull. Nat. Soc. British Columbia, No. 2, 1897, art. 1, 

 p. 14, pi. 1, fi-. 2. 



Shell small, elongate-conic, yellowish white. Nuclear whorls 2, 

 well rounded, smooth. Postnuclear whorls well rounded, appressed 

 at the summit, marked on the first whorl by about 30 slender, pro- 

 tractive, axial threads which are almost as wide as the spaces that 

 separate them. On the second whorl about 42 of the same strength 

 occur; here also the first indication of the more prominent ribs 

 which arc characteristic of the subsequent whorls, occurs. On the 

 third whorl there are 14 slender, narrow, somewhat sinuous, pro- 

 tractive axial ribs which are about one-fourth as wide as the spaces 

 that separate them. In the intercostal spaces of these whorls there 

 arc usually three of the finer riblets described for the whorls above. 

 On the last whorl, the prominent riblets again become enfeebled 

 and the surface is marked by about 36 of the finer threads. Sutures 

 moderately impressed. Periphery of the last whorl well rounded. 

 Base slightly concaved in the middle, marked by the continuations 

 of the axial riblets. Aperture rather large, very oblique, slightly 

 channeled posteriorly; outer lip claw-shaped, effuse, reinforced imme- 

 diately behind the edge by a moderately thick varix; inner lip strongly 

 curved, reflected over and appressed to the base; parietal wall covered 

 with a moderately thick callus which renders the peritreme complete. 



The type, Cat. No. 107421, U.S.N.M., was dredged in 20 fathoms 

 in Cumsheava Inlet, Vancouver Island. It has almost 5 postnuclear 

 whorls and measures: Length, 3 mm.; diameter, 1.1 mm. 



RISSOINA CLEO, new species. 

 Plate 33, fig. 3. 



Shell small, elongate-conic, milk white. Nuclear whorls 2, well 

 rounded, slightly shouldered near the summit. Postnuclear whorls 

 well rounded, very feebly shouldered at the summit, marked by 

 slender, very distantly spaced, somewhat sinuous, decidedly pro- 

 tractive axial ribs, of which 16 occur upon the first, 18 upon the 

 second and third, and 20 upon the jDenultimate wdiorl. Intercostal 

 spaces about four times as wide as the ribs, marked by numerous, 

 fine, irregular wavy markings which give a watered silk effect. 

 Suture moderately coiistricted. Periphery well rounded. Base of 

 last whorl moderately long, concaved in the middle, having a slender 

 fasciolo at its anterior termination, marked by the feeble continua- 

 tions of the axial ribs and the same wavy sculpture observed in the 

 intercostal spaces of the spire. Aperture large, decidedly effuse, 



