1899.] NATURAL SCIENCES OF PHILADELPHIA. 167 



Length of the most perfect specimen, 6 mm. ; diameter, 1 mm. ; 

 length of aperture, about 1 mm. The largest specimen, Avheu 

 perfect, probably measured over 7 mm. 



Nine live and dead specimens (No. 72,055) from St. Thomas, 

 W. I., in the R. Swift collection were labelled as T. imlchella 

 d'Orbiguy (not Odostomia pulchella A. Ad., 1861). That species 

 seems, however, very different, for in a length of 7 or 8 mm. it is 

 described as having but 12 convex whorls with the nucleus, which, 

 according to the figure, is but slightly and peculiarly tilted. The 

 number of transverse ribs is not given, but in the figure there are 

 about 18, nearly perpendicular ones. 



T. Sivifiii differs from T. Penistoni, to which it is closely related, 

 in its much more elongated, more evenly tapered form, deep sutui-e, 

 much narrower, more oblique ribs with Avider interspaces, and espe- 

 cially in its less projecting, oblique nucleus. 



Turbonilla leuca, new species. 



Shell small, slender, white, semitrausparent Avith considerable 

 lustre. Whorls convex, 9 below the prominent nucleus transverse to 

 the axis, with 2^ very projecting whorls. Suture well impressed. 

 Ribs prominent, nearly perpendicular, slightly curved, from 20-24 

 (the last whorl has been injured), separated by little wider, deep 

 spaces, terminating in rounded ends. Base well-rounded. Aper- 

 ture somewhat elongated with curved, little thickened and reflected 

 inner-Hp. 



Length, 4-i- mm. ; diameter, li mm. ; length of aperture, 1 mm. 



One fresh and two dead specimens were found at Bermuda, by 

 Prof. A. E. Verrill and party, 1898. 



Turbonilla Heilprini, new species. Plate VIII, fig. 13. 



Shell small, very slender, gradually tapered, white, semitrauspar- 

 ent, very lustrous, whorls moderately convex, 8 below the promi- 

 nent, slightly oblique, nearly flat nucleus of 1^ but slightly project- 

 ing whorls. Suture distinct, straight. Transverse ribs about 18, 

 straight, nearly perpendicular, clean-cut, rounded, separated by 

 equally wide, deep spaces terminating at the periphery of the body- 

 whorl Avith square-cut ends. Base well-rounded, smooth. Outer- 

 lip broken ; inner-lip thickened. No microscopic striae. 



Length, 2^ mm. ; diameter, about f mm. ; length of aperture, ^ 



