ACHATINIDJE. 63 



CiONELLA, Jeffreys, 1830. 



Syn, — SU'loides, Fitz., 1833. Cochlicopa (part), Moquin- 

 Tandoii, 1855. 



Distr.—lOC^ sp. 



Shell oblong-acuminate or ovate-oblong, striated or smooth, 

 shining; whorls 6-7, the last rounded ; aperture oval, about one- 

 third the total length ; columella short, scarcely truncated, 

 arcuate ; peristome straight, thickened within. 



Zua, Leach, 1820. (Hydastes, Parr., 1849.) Shell ovate- 

 oblong, imperforate, smooth, pellucid, glistening, dark horn- 

 colored ; whorls rather convex ; aperture less than half the total 

 length, ovate; columella more or less truncated; peristome blunt, 

 its margins joined by a callus. G. suhcylindrica, Linn, (xcis, 90). 

 9 sp. Europe, United States, Madeira, Sandwich Isles. 



Hypselia, Lowe, 1854. G. producta, Lowe. 2 sp. Madeira, 

 Morocco. 



C^CTLiANELLA, Fcrussac, 1817. 



Syn. — Cecilioides, Fer.,Blainv., 1817. Polyphemus, Parreyss, 

 1849. Csecilianella, Bourg., 1856, Acicula, Risso, 1826. 



Diatr. — 24 sp. Europe, N. Africa, Cape Yerd Is., W. Indies, 

 Mauritius. G. acicula, Miill. (xcix, 91). 



Shell elongate, imperforate, polished, vitreous, white ; spire 

 turreted with rather obtuse apex ; aperture about half the length 

 of the shell ; columella subarcuate, distinctly truncate ; peris- 

 tome simple, acute. 



The Csecilianellffi are subterranean and nocturnal in habit. 



GEOSTILBIA, Crossc, 1867. Shell imperforate, small, fusiformly 

 cylindrical, thin, hyaline ; apex brusquely rounded and very 

 obtuse ; whorls few ; aperture elongate-pyriform ; peristome 

 simple, slightly thickened ; columellar margin with a shining, 

 transparent, longitudinal lamina, not truncate ; basal margin 

 widely rounded. New Caledonia, India, West Indies. G. Gale- 

 donica^ Crosse. 



Pyrgina, Greef., 1882. 



Distr. — P. umbilicata, Greef. I. of St. Thomas, W. Coast of 

 Africa. 



Shell turreted, closely wound, of twelve or thirteen whorls, in 

 a length of 14 mill.; upper whorls with close, curved costae, 

 rather flat, with deep suture ; last whorl with a carina and 

 rounded basal part, with open, deep umbilicus ; mouth oval, 

 angulated : columella with a spiral fold ; shell white, under a 

 corneous epidermis. 



Rhodea, H. and A. Adams, 1855. 

 Diatr. — 3 sp. New Grenada. R. gigantea, Mouss. (xcix, 88). 

 Shell elongated, cylindrical, subulate, consisting of numerous 



