Verrill and Bush — Marine Mollusca of the Bermudas. 529 



The large, pi'ominent nucleus, consisting of about two whorls, is 

 strongly upturned so as to lie in a plane transverse to the axis of the 

 spire. The aperture is regularly ovate with a somewhat thickened 

 margin, flaring anteriorly. 



Length of the only specimen, S.S'""" ; breadth, 1.35™"°. 



This species is distinguished from other Bermudian Turhonillm by 

 its deep suture, comparatively few longitudinal ribs, and the large 

 nucleus. 



Found in the dredged shell-sand. 



Turbonilla leuca Bush. 



Plate LXIV. Fig. 18. 

 TurboniUa leuca Biish, Proc. Acad. Nat. Sci., Philadelphia, pp. 167, 172, 1899. 

 Rare ; found in the shell-sand. 



Turbonilla Penistoni Bush. 



Plate LXV. Fig. 13. 



Turbonilla pulcheUa Heilprin, The Bermudas, p. 173, 1889 {non d'Orbigny). 

 Turbonilla Penistoni Bush, Proc. Acad. Nat. Sci., .Philadelphia, pp. 165, 172, 

 pi. viii, f. 14, 1899. 



Comparatively rare in the shell-sand. 



Turbonilla Swiftii Bush. 



Plate LXIV. Figs. 21 and 21a. 



Turbonilla Swiftii Bush, Proc. Acad. Nat. Sci., Philadelphia, pp. 166, 173, 1899. 



Two young agree more closely with this than any other described 

 species. 



Found in the shell-sand, 



Pyrgostelis Monte., 1884. Type P. rufa (Philippi). 



Pijrgostelis Monterosato, Norn., Genera and Species, Conch., Med., p. 89, 1884. 

 Tryon, Manual Couch., viii, p. 318, 1886. 



Longitudinal ribs not extending below the periphery of the body- 

 whorl ; interspaces and base cut by equal, or nearly equal, incised 

 spiral lines. Color white, fulvous, or banded. Columella with a more 

 or less prominent reentering fold. In its most extended sense this 

 genus should include all the species, hitherto referred to 2\irbo7ulla, 



