2(i4 RISSOID^. 



mella very broad, expanded, and continuous with the peristome. 

 P. ^i<Z>a,Desh. (Ixxii, 42). Eocene; Grrignon, Paris. 



SETiA, H. and A. Adams. Shell thin, oval-oblong or subconic ; 

 whorls few, ventricose, spotted ; spire short, apex obtuse ; aper- 

 ture suborbicular. Animal with pilose tentacles. B. pulcher- 

 7-ima, Jeffreys (Ixxii, 43). ;• 



CERATiA, H. and A. Adams. Shell subcylindrical, spirally 

 sti'iated, white, thin, subpellucid ; whorls rounded, summit of 

 spire obtuse; aperture suboval ; peristome continuous, the outer 

 lip thin and sharp. Animal with flattened, mostly short and 

 claviform tentacles ; foot bifurcate behind. E. proxima^ Alder 

 (Ixxii, 44). 



ciNGULA, Fleming. Shell thin, elongated, smooth or spirally 

 striate, spotted or banded ; aperture pyriformor oval ; outer lip 

 sharp, with an external varix. B.cingillus ^Montt (Ixxii, 45). 



ONOBA, H. and A. Adams. Shell elongated ; whorls numerous, 

 rounded, spirally striate ; aperture oval; peristome continuous, 

 thick, simple or slightly reflected. B. striata, Mont. (Ixxii, 46). 



ALVANiA, Risso. Shell oval, turbiniform ; spire short, apex 

 sharp; whorls rounded, usually cancellated; aperture subcir- 

 cular, crenulated within ; outer lip with a marginal exterior 

 varix. B. abyssicola, Forbes (Ixxii, 4*7). 



SABAN^A (Leach), Frauenfeld. Shell thick, stout, smooth. 

 Australia, Europe. B. fiammea, Ffauenf. (Ixxii, 48). 



CORENA, A. Ad. Shell elately turbinate, rimate, apex obtuse ; 

 aperture circular, with continuous peritreme ; inner lip with a 

 thin callous expansion, and acute posterior tubercle ; outer lip 

 with duplicated margin, well-reflected. Distr. — 1 sp. Gulf of 

 Suez. 



HEMiSTOMiA, Crosse. Shell subimperforated, elongated, thin ; 

 spire long, summit obtuse, suture well-marked ; aperture ob- 

 liquely semilunar; peristome simple, continuous, almost de- 

 tached; columellar margin very oblique, thickened; basal 

 margin widely rounded. Operculum unknown. New Cale- 

 donia. B. Galedonica, Crosse (Ixxii, 49). 



AMPHiTHALAMUS, Carpenter, 1865. Shell rissoid, with a large 

 nucleus ; inner lip produced, outer lip joining it subposteriorly, 

 suddenly contracted in the adult. Sevei^al minute species. 

 California, Japan. B. incliisa, Carp. 



FENELLA, A. Ad., 1860. Has the pupoid form of Rissoa, with 

 longitudinal and transverse ribs ; the outer lip without a varix. 

 May perhaps belong to Pyramidellidae, with which the animal 

 nearly corresponds. B. pupoides, A. Ad. Japan. 



DiASTOMA, Desh., 1848. Shell turreted, whorls with numerous 

 transverse ribs, and with a few intermediate varices. Inner 

 margin of the aperture partially detached from the previous 

 whorl; the aperture itself is strongly contracted posteriorly. 



