NO. 2193. WEST AMERICAN MARINE M0LLUSK8—BARTSCH. 643 



ill the first of which the side of the last vohition is about one-fifth 

 immersed. Postnnclear whorl well rounded, slightly curA-ed at the 

 aj^pressed summit, marked by rather distantly spaced, slender, nar- 

 row, well-rounded axial ribs, which become somewhat flattened and 

 enfeebled toward the summit. Of these ribs 18 occur upon the first, 

 16 upon the second to fourth, and 18 upon the remaining turns. 

 Intercostal spaces about two and one-half times as wide as the ribs, 

 terminating at little posterior to the suture, thus leaving a very 

 narrow plain band between their termination and the summit of the 

 succeeding turn. Suture moderately constricted. Periphery of the 

 last whorl well rounded. Base short, strongly rounded, marked by 

 the feeble continuations of the axial ribs, which become evanescent 

 before reaching the middle of the base. Entire surface of the shell 

 crossed b}^ rather marked, subequally strong and subequally spaced 

 deepl.y incised spiral striations. Aperture subquadrate; i^osterior 

 angle obtuse (outer lip partly fractured) ; inner lip thick, almost 

 straight, and somewhat revolute, provided with an obsolete oblique 

 fold a little anterior to its insertion; parietal wall glazed by a fine 

 callus. 



The type, Cat. No. 268719, U.S.N.M., was dredged by the U. S. 

 Bureau of Fisheries steamer Albatross at station 5678, off Redondo 

 Point, Magdalena Bay, Lower California, in 13| fathoms, on broken 

 shell bottom. It has 8 postnuclear whorls and measures — length, 

 1.2 mm. ; diameter, 1.3 mm. The unique type is an adolescent shell, 

 and it is quite possible that when adult specimens are obtained it will 

 be found that the axial ribs terminate at the periphery instead of 

 continuing feebly upon the base. 



TURBONILLA (STRIOTURBONILLA) REDONDOENSIS. new species. 



Plate 42, fig. 4. 



Shell large, broadly elongate conic, yellowish white. Nuclear 

 whorls decollated. Postnuclear whorls strongly rounded, with a 

 strong sloping shoulder which extends over the posterior two-fifths 

 of the whorls. Surface marked by strong, distantly spaced, well- 

 rounded, regular, lamellose, slightly curved, protractively slanting 

 axial ribs, of which 14 occur upon the first three whorls and 16 upon 

 the rest except the last, which has 18. These ribs become somewhat 

 enfeebled and flattened toward the summit and terminate at the pe- 

 riphery. Intercostal spaces about double the width of the ribs, shal- 

 low, terminating a very little posterior to the suture, thus leaving a 

 very narrow smooth band immediately posterior to the summit of 

 the succeeding turn. Suture quite strongly constricted. Periph- 

 ery of the last turn obscurely angulated. Base short, almost flat- 

 tened, marked by fine incremental lines and fine, rather regularly 



