PUNCTURELLA. 245 



This species varies with respect to the size of the tubercles or 

 papillse. Some recent and fossil specimens have very few and slight 

 scattered tubercles, or are nearly smooth. The recent are rather 

 larger than the fossil specimens, and have usually stronger tubercles. 

 (Jeffreys.) 



P. ROSTRATA Segueuza. PI. 25, fig. 25 ; pi. 64, figs. 30, 31. 



Shell small, ovate, conic, much elevated, a little curved or sub- 

 rostrate ; apex subacute ; aperture small, ovate ; internal plate 

 large, with two scarcely distinct lateral sulci outside corresponding 

 to it. Surface ornamented with minute rounded granules. Length 

 5, breadth 3-5, alt. 4'6 mill. (%.) 



Bay of Biscay ; North Atlantic. Fossil in the Miocene f and Pli- 

 ocene of Sicily. 



F. rostrata SEG., 1. c. p. 84, t. 4, f. 3, 3a, 3b, 3c. Jeffreys, P. Z. S. 

 1882, p. 675. 



Seguenza's description and figures are given. 



Var. TRIANGULATA Dall. 



Shell very small, thin and high, ovate, with slightly impressed 

 sides, glassy, dotted in regular oblique-curving lines, with high, 

 blunt, minute, glassy tubercles ; the side slopes are high and 

 straight, the front edge faintly convex, the back slope slightly con- 

 cave ; there is no embryonic apex ; and the slit is a round hole 

 parallel to the base. Sculpture: The surface of the shell is glassy, 

 but is dotted with minute tubercles which are generally parted by 

 more than their own diameter and run in very regular oblique 

 sweeps parallel to one another. Color transparently glassy, the 

 tubercles being dead white. Apex none, the top being slightly 

 bent back and the entire tip removed. Slit : A small round hole 

 on the very top, with slightly irregular sides. Margin very thin ; 

 the sides are almost straight or a little bent in, and the breadth is 

 very slightly greater behind than before. Inside quite glassy ; 

 there is no anterior furrow, and the straight concave-edged septum 

 runs far down the shell parallel and very near to the posterior wall, 

 thus cutting off a long sheath-like process. Length O13, breadth 

 0-08, alt. 0-12 inch. (Wats.) 



Off Culebra Island, 390 fms. ; Off Campeche, Yucatan, 200 fms. 



P. (Fissurisepta) rostrata WATSON, Challenger Gastrop., p. 48. 

 Fissurisepta triangulata DALL, Blake Gastrop., p. 404. 



