282 PUNCTURELLA. 



P. cooperi CPR., Moll, of Western N. A. p. 137, Smithsonian 

 Misc. Coll. 252 ; Proc. Cal. Acad. N. S. iii, p. 214, 1865. 



P. CUCULLATA Gould. PI. 42, figs. 72, 73, 74, 75 ; pi. 63, figs. 38, 

 39. 



Shell large for the genus, short, oval, conical, the recurved apex 

 about in the center, fissure in front of the summit, wedge-shaped, 

 rather short ; slopes straight ; sculptured with numerous radiating 

 riblets, every fourth one larger, or in younger shells every alternate 

 one larger ; having rather coarse concentric stria?. 



Interior white; septum short, arched, without buttresses, not con- 

 cealing the fissure, which continues downward in a groove which 

 does not extend to the edge of the shell. 



Length 22, breadth 18, alt. 12 mill. 



Monterey ; Puget Sound ; Neeah Bay. 



Rimula cucullata OLD. Proc. Bost. Soc. N. H. ii, p. 159, 1846 ; U. 

 S. Expl. Exped. Sh., p. 368, f. 475. 



The largest species. The short, arched septum, without side 

 buttresses, and the shorter fissure separate this from P. noachina, etc. 

 The fissure is wedge-shaped, acute anteriorly, rounded behind. 



P. CLATHRATA Jeffreys. PI. 27, figs. 66, 67. 



Shell small, porcellanous^ oblong, scarcely perceptibly broader in 

 front; its slopes are conical and straight till close to the top, which 

 projects backwards but little; there are strongish ribs and still 

 stronger concentric threads ; the slit is short and broad. Sculpture : 

 there are about 35 strongish rounded riblets with feebler ones be- 

 tween, bringing up the total number to 60 or 70; overlying these, 

 and forming minute knots at the crossings, are rather stronger, con- 

 centric rounded threads, giving to the surface a wattled appearance. 

 Color faintly brownish-gray. Apex rather coarse, curled in, but 

 very little reverted or flattened; there are just two whorls in all. 

 Slit oblong, being short and broad ; as seen from without, one-half 

 is open leading into the interior, the other is closed by the very 

 curved septum. Margin crenulated and crimped by the ribs. In- 

 side glassy, blunt at the top, not being hollowed into the apex, 

 strongly furrowed by the ribs, less so by the concentric threads; 

 there is no anterior furrow seen from within, the slit is semi-oval, 

 and the strong septum is excessively short and straight and is 

 almost perpendicular ; from it a slight callus encircles the opening 

 of the slit. Length 0'25, width 0'16, alt. 0'13 inch. (Wats.) 



