520 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxiii. 



Subgenus MENESTHO MoUer. 

 Menestho Moller, Ind. Moll. Greenl., 1842, p. 10. 



Shell not umbilicated, marked by moderatel}" well-developed and 

 usLiall}^ equally spaced spiral cords; axial sculpture reduced to mere 

 lines of growth which frequently appear as very slender raised threads 

 in the grooves between the cords. 



Type. — Turho alhidus Fabricius. 



KEY TO SPECIES OF MENESTHO. 



Spiral sculpture very regular and equally spaced. 



Shell large, adult over 3.5 mm. in length exam. 



Shell very small, adult under 2.5 mm. in length pharcida. 



Spiral sculpture irregular, not equally spaced liarfordensis. 



ODOSTOMIA (MENESTHO) PHARCIDA, new name. 



Plate XL VI, fig. 8. 



Mumiola tenuis D.\ll, Bull. Nat. Soc Brit. Col, 1897, p. 14, pi. i, fig. 10. Not 

 Odoslomia tenuis Carpenter, 1856, not Odoalomia /r>im.s Jeffrey, 1884. 



Shell small, subcylindric, yellowish -white. Nuclear whorls deeply 

 immersed, a portion of the last and the penultimate only appear when 

 viewed from the side; this gives the shell a truncated appearance. 

 Post-nuclear whorls moderately well rounded, rather wide between the 

 sutures, and somewhat shouldered at the summits; ornamented by 

 strong, low, rounded spiral cords, which are separated by moderately 

 deep, narrow, depressed channels. Six of these cords occur upon the 

 first, 7 upon the second to the penultimate whorl between the sutures; 

 the posterior cord is a little ])roader and less elevated than the rest, 

 while some of tho.se on the penultimate turn show a tendency to 

 divide, that is, a faint spiral line is apparent on the middle of some of 

 these cords. Sutures well impressed. Periphery and base of the last 

 whorl well rounded, the latter ornamented by 8 rounded spiral cords 

 similar to those l^etween the sutures. The spaces between the spiral 

 ridges on the base and between the sutures are marked by closely 

 placed, exceedingly slender, raised axial threads. Aperture pA'riform, 

 somewhat efJuse anteriorly, posterior angle acute; columella short, 

 curved, reenforced b}" the attenuated base, free only at its extreme 

 anterior end, with an oblique fold near its insertion; parietal wall 

 covered by a thin callus. 



The type (Cat. No. 107440, U.S.N.M.) was dredged by Dr. C. F. 

 Newcombe, in 10-15 fathoms, at Curashewa Inlet, Queen Charlotte 

 Island, British Columbia. It has 4 postnuclear whorls, which measure: 

 Length 2.2 mm., diameter 0.9 mm. 



