no. 1823. MOLLUSKS OF THE GENUS CERITHIOPSIS— BARTSCH. 363 

 CERITHIOPSIS MONTEREYENSIS, new species. 



Plate 41, fig. 5. 



Shell small, broadly conic, light brown. (Nuclear whorls decol- 

 lated.) Post-nuclear whorls marked by three spiral cords, the first 

 of "which (which is very poorly developed, in fact almost obsolete on 

 the early whorls) is at the summit, while the next is separated from 

 it by a narrow channel, the third being about as far posterior to the 

 suture as the second is from the first, and the space between the second 

 and third being double the width of that between the first and 

 second. In addition to the spiral cords, the whorls are marked by 

 vertical, axial ribs which are equal to the spiral cords in strength. 

 Of these ribs, 15 occur upon the second and third, 16 upon the fourth 

 and fifth, 18 upon the sixth, and 22 upon the penultimate turn. 

 The junctions of the axial ribs and spiral cords form cusp-like 

 tubercles, while the spaces inclosed between them are very elongate 

 rectangular pits between the first and second spiral cord, and strongly 

 impressed, squarish pits between the second and third. Suture well 

 impressed. Periphery of the last whorl marked by a narrow keel 

 which is separated from the supraperipheral keel by a sulcus as wide 

 as that separating the first from the second spiral cord, and crossed 

 by the continuations of the axial ribs which terminate at its posterior 

 border. Base short, slightly rounded, ornamented with three nar- 

 row, spiral keels, of which the first two are much stronger than the 

 other. These keels are equally spaced between the periphery and 

 the middle of the base, which is occupied by the last one. In addi- 

 tion to the above sculpture, the entire surface of spire and base is 

 marked by numerous, fine incremental lines. Aperture subquadrate, 

 decidedly channeled anteriorly; posterior angle obtuse; outer lip 

 rendered strongly wavy by the external sculpture, which is apparent 

 in the aperture; columella short, stout, curved and decidedly twisted, 

 the free edge reflected; parietal wall glazed with a thin callus. 



The type (Cat. No. 32395, U.S.N.M.) comes from Monterey Harbor, 

 California. It has eight post-nuclear whorls and measures: Length 

 3.2 mm., diameter 1.3 mm. 



CERITHIOPSIS INGENS Bartsch. 



Piute 41, fig. 4. 

 Bittium quadrifilatum ingens Bartsch, Proc. TJ. S. Nat. Mus., vol. 33, 1907, p. 180. 



Shell large, elongate-conic, white. Nuclear' whorls decollated. 

 Post-nuclear whorls slightly shouldered at the summit, moderately 

 well rounded, marked on the first three turns by three spiral cords. 

 On the fourth turn a fourth cord makes its appearance at the summit, 

 rapidly increasing in strength until on the last three whorls it is quite 

 equal to the other cords. These spiral cords are almost as wide as 



