no. 1823. MOLLUSKS OF THE GENU8 CERITHIOPSIS— BARTSCH. 359 



CERITHIOPSIS ANTEMUNDA, new species. 

 Plate 36, fig. 4. 



Shell elongate-conic, brown. (Nuclear whorls decollated.) Post- 

 nuclear whorls appressed at the summit, very slightly rounded, 

 marked by three spiral cords, of which the first — which is at a little 

 distance anterior to the summit — is obsolete on the first four whorls, 

 giving them a decidedly shouldered appearance, while on the last 

 turn it is almost equal to the other two. The second cord is a little 

 posterior to the middle between the sutures, while the third one is a 

 little posterior to the suture. The spaces between these spiral cords 

 are about double the width of the spiral cords. In addition to the 

 spiral sculpture, the whorls are marked by slender, well rounded, 

 retractive axial ribs, equaling the spiral cords in strength. Of 

 these ribs, 14 occur upon the first to fourth, 16 upon the fifth and 

 sixth, and 20 upon the penultimate turn. The junctions of the 

 axial ribs and spiral cords form well-rounded tubercles, while the 

 spaces inclosed between them are strongly impressed, squarish 

 pits. Sutures strongly channeled, showing the posterior edge of 

 the peripheral cord. Periphery of the last whorl marked by a strong, 

 spiral cord, which is separated from the supraperipheral cord by a 

 sulcus as wide as that which separates the supraperipheral from the 

 median cord, and like it is crossed by the continuations of the axial 

 ribs, which extend to the posterior edge of the peripheral cord. Base 

 concave, with a slender fasciole surrounding the insertion of the 

 columella and marked axially with fine, incremental lines, which 

 also extend over the entire surface of the spire. Aperture sub- 

 quadrate, strongly channeled anteriorly; posterior angle decidedly 

 obtuse; outer lip thin, showing the external sculpture within, rendered 

 sinuous at the edge by the external sculpture; columella stout, twisted, 

 with the edge reflected; parietal wall covered with a thin callus. 



The type and another specimen (Cat. No. 195188, U.S.N.M.) 

 come from San Pedro Bay, California. The type has lost the nucleus. 

 The eight whorls remaining measure: Length 5 mm., diameter 1.9 mm. 

 Another specimen (Cat. No. 213313, U.S.N.M.) was dredged by the 

 U. S. Bureau of Fisheries steamer Albatross at station 2932 in 20 

 fathoms on sand bottom, bottom temperature 58°, off San Diego, 

 California. 



CERITHIOPSIS DIOMEDEiE, new species. 



Plate 37, fig. 5. 



Shell small, elongate-conic, brown. (Nuclear whorls decollated.) 

 Post-nuclear whorls with a strongly channeled suture in which the 

 posterior edge of the peripheral cord is apparent on all the whorls; 

 marked by three spiral cords, of which the first is considerably weaker 

 than the other two and is situated at the summit, rendering this some- 



