Abt. 11 NEW AMEEICAlSr MAEINE MOLL.TJSKS BABTSCH 23 



the first from the peripheral sulcus. There is no spiral cord at 

 the insertion of the columella. Aperture decidedly channeled anteri- 

 orly; posterior angle obtuse; outer lip thin, rendered wavy at the 

 edge by the external sculpture, which is visible through the sub- 

 stance of the shell; inner lip decidedly sinuous, reflected over and 

 appressed to the columella ; parietal wall provided with a thin callus. 



The type, Cat. No. 340858, U.S.N.M., was collected by Mrs. Old- 

 royd at Clayoquot, British Columbia. It has nine and a half post- 

 nuclear whorls and measures, length, 6.5 mm. ; diameter 2. 3 mm. 



I named this species for Dr. C. M. Frazer, Director of the Bio- 

 logical station, Nananimo, British Columbia. 



Another specimen. Cat. No. 340856, U.S.N.M., was collected by 

 Mrs. Oldroyd. It comes from Victoria, British Columbia, and Cat. 

 No. 340857, U.S.M.N., two specimens, were likewise collected by 

 Mrs. Oldroyd at Nanaimo, British Columbia. Additional specimens 

 of this species are in Mrs. Oldroyd's collection. 



CERITHIOPSIS (CERITHIOPSINA) WILLETTI Bartsch 



Plate 5, fig. 1 



Cerithiopsis {Cerithiopsina) uHlletti Bartsch, Proc. Biol. Soc. Wash., 

 vol. 34, 1921, pp. 36-37. 



Shell large, robust, elongate-conic, pale brown. All but the last 

 nuclear whorl decollated. This shows, however, that the species 

 belongs to the subgenus Cerithiopsina. Postnuclear whorls crossed 

 by very strong, almost sublamellar, rather coarse, rounded, protrac- 

 tively slanting axial ribs, of which 16 occur upon the first to fifth, 

 18 upon the sixth, 20 upon the seventh, and 24 upon the last turn. 

 Intercostal spaces about two-thirds as wide as the ribs. In addi- 

 tion to the axial ribs there are three strong spiral cords, of which 

 the first is about as far anterior the summit of the whorls as it is 

 distant from its median neighbor. The first of these spiral cords 

 is a little less strongly developed on the earlier whorls than on the 

 succeeding turns, where it almost equals the other two. The junction 

 of the axial ribs and the spiral cords forms strong tubercles, of 

 which those on the cord at the summit are well rounded, while those 

 on the median cord are truncated posteriorly and slope gently 

 anteriorly. The same is true of the suprasutural cord. On the last 

 whorl, however, the tubercles are more elongated and the truncation 

 at the anterior margin is less pronounced, the long axis of the 

 tubercles coinciding with the axis of the shell. The spaces inclosed 

 between the axial ribs and spiral cords are well-rounded pits. The 

 summit of the whorls falls a little anterior to the peripheral cord 

 and lets this appear as a narrow, smooth, sinuous thread in the some- 

 what constricted suture. Periphery of the last whorl marked by a 



