294 American Seashells 



shallow suture bearing axial ridges, and with the shoulder of the outer lip 

 bearing a small, triangular projection. Uncommonly collected. 



Family CAVOLINIDAE 



Shell symmetrical (not coiled), fragile, white to brown, and of various 

 shapes — needle-like, cylinder-shaped, flattened triangular or bulbous. 



Genus Creseis Rang 1828 

 Shell a long cone, almost circular in cross-section, needle-like. 



Creseis acicida Rang Straight Needle-pteropod 



Figure 6411 



Atlantic and Pacific, pelagic. (N. Lat. 48° to S. Lat. 40°). 



20 to 33 mm. (about an inch) in length. A long, straight, slender cone 

 tapering to a sharp point. Styliola vitrea Verrill and conica Esch. are this 

 species. 



Creseis virgula Rang Curved Needle-pteropod 



Figure 64P 



Atlantic and Pacific, pelagic. (N. Lat. 41° to S. Lat. 35°). 



8 to 10 mm. in length. A drawn-out, slender shell similar to acicula, 

 but with its narrow end hooked to one side. The amount of bend of hook 

 is variable. Hyalaea conijormis Orb. and Cleodora virgula Soul, and Eyd. are 

 the same. 



Genus Styliola Lesueur 1825 

 Styliola siibula Quoy and Gaimard Keeled Clio 



Figure 64-0 



Worldwide in warm seas, pelagic. 



10 mm. in length, conical, straight, considerably elongated. The surface 

 is smooth, and with a dorsal groove not parallel to the axis of the shell, but 

 slightly oblique, turning from left to right, with only the anterior extremity 

 (which ends in a rostrum) in the median line. There is only one species in 

 the genus and it is world-wide in distribution. 



Genus Hyalocylis Fol 1875 

 Hyalocylis striata Rang Striate Clio 



Worldwide m warm seas, pelagic. 



