44 THE NAUTILUS. 



Alt. 8, diam. 10 mm. ; diam. of aperture, with periatome 4.5 mm. 



Alt. 7, diam. 9 mm. 



Farallones east of Hermitage, Charles Wright. 



This form is described and figured from specimens determined by 

 Professor de la Torre, for comparison with the preceding. It is not 

 uncommon in the older collections, under the name " Choanopoma 

 alatum Pfr." Pteiffer's species is larger, more solid, opaque fleshy- 

 white, with the interior orange ; the aperture is much more oblique 

 and the sculpture entirely different. 



CHONDROPOMA CARENASENSE n. sp. 



The shell is perforate, tapering-cylindric, truncate, about 3 

 whorls remaining; very pale brown, with small often indistinct dark 

 spots arranged in vertical series at irregular intervals, sometimes 

 having 5 or 6 narrow, faint, spiral bands, with spots as above. 

 Sculpture of many fine spiral cords, 10 to 14 on the penult whorl 

 crossed by more closely set vertical lamina-like threads which have 

 small nodes where they cross the spirals, and finely crenulate the 

 suture, where each stands separate. Whorls convex, the last 

 ascending a little in front. Aperture ovate ; peristome expanded, 

 built out in a narrow flat margin, widest as the columeller margin 

 and at the posterior angle, where it ascends in a very short lobe or 

 obtuse point ; parietal margin appressed to the preceding whorl. 

 The operculum retracts about one-fourth of a whorl within, is light 

 brown, with a spiral convexity just outside the suture. 



Length 12.5, diam. 7.5 mm. ; length of aperture with peristome 

 6 mm. 



Length 12, diam. 7 mm.; length of aperture with peristome 5.7 

 mm. 



Length 10.3, diam. 6 mm. ; length of aperture with peristome 5 

 mm. 



Cayo Carenas, in Cienfuegos Bay, Pilsbry, 1903, and Henderson 

 1910. 



C. candeanum (Orbigny) tapers more, to a narrower truncation, 

 and the sutural denticulation is more widely spaced. In C. caren- 

 asense every vertical thread denticulates the suture, none being 

 united or dropped out there. It is an abundant snail on Cayo 

 Carenas, a tiny islet now nearly covered with residences. 



