ACHATINID A. 63 
CionELLA, Jeffreys, 1830. 
Syn.—Styloides, Fitz., 1833. Cochlicopa (part), Moquin- 
Tandon, 1855. 
Distr.—106 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 bya callus. C.subcylindrica, Linn. (xcix, 90). 
9 sp. Europe, United States, Madeira, Sandwich Isles. 
Hypselia, Lowe, 1854. CO. producta, Lowe. 2sp. Madeira, 
Morocco. 
C HCILIANELLA, Ferussac, 1817. 
Syn.—Cecilioides, Fer., Blainv.,1817. Polyphemus, Parreyss, 
1849. Cecilianella, Bourg., 1856. Acicula, Risso, 1826. 
Disir.—24 sp. Europe, N. Africa, Cape Verd Is., W. Indies, 
Mauritius. C.acicula, Mull. (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 Cecilianelle are subterranean and nocturnal in habit. 
GEOSTILBIA, Crosse, 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. C. Cale- 
donica, Crosse. 
Pyraina, 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 coste, 
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. 
RuopEa, H. and A. Adams, 1855. 
Distr.—3 sp. New Grenada. R. gigantea, Mouss. (xcix, 88). 
Shell elongated, cylindrical, subulate, consisting of numerous 
