284 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.40. 



irregular. A raised spiral cord of moderate strength marks the inser- 

 tion of the columella; the space between this and the peripheral cord 

 is a deep sulcus, which, like the rest of the base is crossed by fine 

 incremental lines. The anterior half of the base, which is fairly- 

 rounded, is marked by six irregular wavy, fine, raised, spiral threads. 

 Aperture irregularly rhomboid, very strongly channeled anteriorly, 

 and feebly so at the posterior angle; outer lip moderately thick, 

 showing the external sculpture and color markings within; inner lip 

 reflected over the base; parietal wall covered with a thick callus which 

 renders the peritreme complete. 



The type has seven post-nuclear whorls and measures: Length 2.5 

 mm., diameter 1 mm. It and two specimens form Cat. No. 221616, 

 U.S.N.M. 



CERITHIOPSIS VICOLA, new species. 

 Plate 35, fig. 12. 



Shell elongate-conic, white, with two bands of golden brown on each 

 whorl. The first of these bands extends over the posterior row of 

 tubercles, while the second covers the peripheral cord. Nuclear 

 whorls two and one-half, well rounded, smooth. Post-nuclear 

 whorls well rounded, marked from the very beginning with three 

 strong spiral cords, which are about as wide as the spaces that 

 separate them. The first of these cords, which is at the summit, is a 

 trifle weaker than the rest ; the third is at some little distance above 

 the suture, while the second is half way between the two. In addi- 

 tion to these cords, the whorls are marked by well developed vertical 

 axial ribs, which are about as strong as the spiral cords. Of these 

 ribs, 18 occur upon the first and second, 20 upon the third, 22 upon 

 the remaining whorls. The junctions of the axial ribs and the spiral 

 cords form well developed tubercles, while the spaces inclosed between 

 them are well impressed, squarish pits. The tubercles are well 

 rounded on the first and second cords, while those on the third are 

 truncated posteriorly, sloping gently anteriorly. Sutures strongly 

 impressed, showing a portion of the peripheral cord on the last three 

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

 which is separated from the suprasutural cord by a space almost 

 double the width of that which separates the suprasutural from the 

 median cord. The axial ribs extend to the posterior edge of the 

 suprasutural cord, but do not cross it. Base moderately long, some- 

 what concave, marked by a low tumid area at the insertion of the 

 columella, which somewhat suggests a very broad, low, weakly 

 rounded cord. The entire surface of the base is marked with exceed- 

 ingly fine spiral striations and incremental lines. Aperture very large, 

 irregular, oval, decidedly effuse at the junction of the outer and basal 

 lip, very strongly channeled anteriorly and slightly so at the posterior 



