54 BULLETIN 68, UNITED STATES NATIONAL MUSEUM. 



TURBONILLA (STRIOTURBONILLA) ARESTA, new species. 



Plate 4, figs. 5, 5a. 



Shell very slender, milk-white. Nuclear whorls small, two and 

 one-half, forming a moderately elevated, hehcoid spire, which has 

 its axis at right angles to that of the succeeding whorls, and is not 

 at all immersed. Post-nuclear whorls moderately rounded, marked 

 by sublamellar, protractive axial ribs, which extend undiminished to 

 the summit of the whorls, rendering this crenulated. There are 14 

 of these upon the first three whorls, 16 upon the fourth to eighth, 

 18 upon the ninth, 20 upon the tenth and eleventh, and 21 upon the 

 penultimate turn. Intercostal spaces about one and one-half times 

 as wide on all but the last three whorls ; on the latter they are about as 

 wide as the ribs and terminate a little posterior to the suture. Sutures 

 strongly marked. Periphery of the last whorl faintly angulated. 

 Base short, well rounded. Aperture moderately large, subquadrate, 

 posterior angle obtuse. Outer lip thin, bent almost at right angles 

 to the anterior lateral angle. Columella slender, slightly curved and 

 slightly re volute. 



The type (Cat. no. 206858, U.S.N.M.) has thirteen post-nuclear 

 whorls and measures: Length 6.4 mm., diameter 1.2 mm. It was 

 dredged off Catalina Island, together with nine additional specimens, 

 by the University of California. Five additional specimens were 

 dredged by the same institution off San Diego. Another specimen 

 (Cat. no. 163252, U.S.N.M.) was dredged at U. S. Bureau of Fisheries 

 station 2901 , off Santa Rosa Island, in 4S fathoms. Another specimen 

 (Cat. no. 206863, U.S.N.M.) comes from San Diego. 



TURBONILLA (STRIOTURBONILLA) PAZANA, new species. 

 Plate 4, figs. 13, 13rt. 



Shell very slender, elongate-conic, milk-white. Nuclear whorls 

 two and three-fourths, forming a decidedly elevated spire, the axis 

 of w^hich is at a right angle to that of the succeeding turns, in the 

 first of which it is scarcely at all immersed. Post-nuclear whorls 

 moderately rounded, with very feebly shouldered summits, orna- 

 mented with well-developed narrow protractive axial ribs, 14 occur 

 upon the first to tenth, and 16 upon the remaining turns. Inter- 

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

 well impressed, marked by exceedingly fine, closely spaced, spiral 

 striations. Sutures well impressed, rendered somewhat sinuous by 

 the ribs. Periphery of the last whorl somewhat angulated. Base 

 short, well rounded, marked by fine spiral striations. Aperture 

 rather long, rhomboidal; posterior angle obtuse; outer lip thin, 

 showing the external sculpture within; columella moderately strong, 

 curved, and slightly revolute. 



