178 MANUAL OF THE MOLLTJSCA. 



Shell globose, depressed or keeled, caUous beneath ; aperture squarish or 

 semi-lunar ; columella flattened ; peristome simple, expanded ; operc. shelly 

 or membraneous, squarish or semi-ovate, lamellar. 



AnimalXske. Cyclophorus ; lingual teeth 3.1.3. (Gray.) 



Distr. 150 sp. W. Indies, 50 ; Tropical America, 44 ; Pacific Ids., 26 ; 

 Australian Ids. 3 ; Philippines, 7. 



Suh-genera. Lucidella, (aureola) Gray. Peristome more or less toothed 

 internally ; 8 sp. W. Indies, Tropical America. 



Trochatella (pulcheUa), Sw. ^/ig//not callous beneath; peristome simple, 

 expanded. W. Indies 16 sp. Venezuela 1. 



Alcadia, Gray. A. Brownei, PI. XII. fig. 43. Jamaica. Shell helix- 

 shaped, often velvety, callous beneath ; columella flattened, straight ; peris- 

 tome slit in front; operc. sheUy, semi-ovate, with a tooth-like process adapted 

 to the slit in the peristome. Listr. 17 sp. Cuba, Jamaica and Haiti. 



Stoastoma, C. B. Adams. 



Etym. Stoa pillared, stoma, month. Type, S. pisum. Ad. 



Shell minute, globose-conic or depressed, spirally striated; aperture 

 semi-oval ; peristome continuous ; inner margin straight, forming a small 

 spu-al keel round the umbilicus ; operc. sheUy, lamellar. 



Blstr. 19 sp. Jamaica. ^S". succineum (Electrina, Gray) has smooth 

 whirls. I. Opara, Polynesia. 



FAMILY VII. ACICULID.E. 



Shell elongated, cylindrical ; operculum thin, sub-spiral. 



Animal \^\}a. the muzzle rather produced, slender and truncated; eyes 

 sessile on the upper part of the head, behind the base of the slender tentacles ; 

 foot oblong, short, pointed behind. 



AcicuLA, Hartmann. 



Type, A. fusca, PI. XII. fig. 44. Syn. Acme and Acmaea, Hartm.* 



Shell minute, slender, nearly imperforate ; peristome slightly thickened, 

 margins sub-paraUel, joined by a thin callus ; operc. hyaline. 



Distr. 5 sp. Brit. Germany, Prance; Vanicoro (on leaves). A. fusca 

 is found in low, marshy situations, at the roots of grass ; it occurs fossil in 

 the Newer Pleiocene of Essex (J. Brown). 



Geo:melania. Pfeiffer. 



Type. G. Jamaicensis. Pfr. Ehjm. Ge, the ground (i.e. terrestrial). 



5/«^/nmperforate, turreted; aperture entire, effused; peristome simple, 

 expanded; mai-gins joined, basal produced into a tongue-shaped process; 

 operc. oval, pellucid, whirls few, rapidly enlarging. 



Distr. 21 sp. Jamaica. 



* All given in the same year, 1821; the name Jcmaea having been employed by 

 Eschscholtz for a genus of limpets, Acicula has been retained by Pfeiffer and Gray 

 for this land-shell. 



