292 HELICINID^. 



, Alcadia, Gray. 



Distr. — 28 sp. West Indies. A. Brownii (Ixxvii, 39). 



Shell Helix-shaped, often velvety, callous beneath ; columella 

 flattened, straight ; peristome slit in front. Operculum shelly, 

 semiovate, with a tooth-like process adapted to the slit in the 

 peristome, 



LuciDELLA, Swainson. 



Distr. — 5 sp. West Indies. L. aureola, Yer. (Ixxvii, 40). 



Shell depressed, heliciform, slightly callous at the base ; aper- 

 ture triangular, sinuous ; peristome thickened, with superior and 

 inferior tooth-like internal laminae. Operculum membranous. 



BouRCiERA, Pfeiffer. 



Distr. — 2 sp. Equador. B. heliciniformis, Pfr. (Ixxvii, 

 41,42). 



Shell heliciniform, subglobose; aperture oval; peristome ex- 

 panded, produced at the base. Operculum paucispiral, corneous. 



Bourciera absorbs away the inner whorls of the shell, like 

 Helicina ; its dentition also agrees with that group. 



Stoastoma, C. B. Adams. 



Etym. — Stoa, pillared, stoma., mouth. 



Syn. — Hemicyclostoma, C. B. Ad. 



'jpistn — 83 sp. One in Isle of Opara, Philippines, one in Hayti ; 



" , -all the others in Jamaica. S. pisum, C. B. Ad. (Ixxvii, 43). 



'^> Shell minute, globose-conic or depressed, spirally striated; 



aperture semioval ; peristome continuous ; inner margin straight, 



forming a small spiral keel round the umbilicus. Operculum 



shelly, lamellar. 



ELECTRiNA, Gray. Shell smooth. S. succinea, Sowb. (Ixxvii, 

 44), is the only species. 



WILKINSON^A, Chitty, 185t. Shell subdiscoidal, spirally car- 

 inated, last whorl much produced. ;S. Wilkinsoneanum, Chitty . 



FADYENiA, Chitty, 1851. Shell with the spire depressed, sub- 

 angular on the upper part of the last whorl, subplanate at the 

 periphery, subangulated below, and subplanate round the umbil- 

 icus. S. Fadyenianum, C. B. Ad. 



METCALFEiA, Chitty, ISST. Shell depressed conic. *S. ■Me'^caZ/e- 

 ianum, Chitty. 



PETiTiA, Chitty, 1857. Shell globose, discoid. S. Petitianum, 

 C. B. Ad. 



LiNDSLEYA, Chitty, 1851. Shell globose, conic. S. Lindsley- 

 anum, C. B. Ad. 



BLANDiA, Chitty, 1851. Shell subdiscoidal. S. Blandianum, 

 C. B. Ad. 



LEWisiA, Chitty. Shell subdiscoidal ; aperture semiovate ; 

 peristome continuous, with a spiral callus at the base excessively 



