292 MANUAL OF THE MOLULUSCA. 
Zua, Leach. Z. lubrica, Pl. XII., Fig. 14. 
Shell polished, columella shghtly truncated. 6 species, 
Azeca, Leach. A. tridens, Pl. XII., Fig. 15. 
Shell polished, peristome thickened and toothed. 4 liying 
species. 
Distribution, 1,120 species. Universally distributed. 
Fossil, 30 species. ocene—. LHurope, St. Helena, Australia, 
West Indies. 
B. Guadalupensis occurs in modern limestone, with human 
remains. 
AcHATINA, Lamarck. Agate-shell. 
Type, A. yariegata, Pl. XII., Fig. 22. 
Synonyms, Cochlitoma, Fér. Columna, Perry. Subulina 
(octona), Beck. Liguus(virgineus), Montf. Cionella (acicula), 
Jeffreys. 
Shell imperforate, bulimiform; columella twisted, and trun- 
cated in front; aperture oval, angular above ; peristome simple. 
acute. 
Animal snail-like. The great African Achatinee are the 
largest of all land-snails, attaining a length of eight inches; 
their eggs exceed an inch in length, and have a calcareous 
shell. 
Distribution, 370 species. Europe, Africa, Asia, and tropical 
America. 
Fossil, 19 species. Eocene—. Europe and St. Helena. - 
Sub-genera. Glandina (yoluta), Schum. (Oleacina, Bolten; 
Polyphemus, Montf.) 
Shell oblong, fusiform ; aperture narrow, elliptical. 
Animal twice as long as the shell; eye tentacles deflected at 
the tips, beyond the eyes ; vibracula much shorter, also deflected; 
lips elongated, tentacular. Frequentslow and moist situations; 
in confinement one refused vegetable food, but ate another 
snail. (Say.) 186 species. West Indies, Central America, 
Mexico, Florida. 
Fossil. Eocene—. Glandina costellata. Isle of Wight. (FE. 
idwards.) 
Achatinella (vulpina), Sw. (Helicteres, Fér.) Columella 
twisted into a strong, tooth-like fold. Sandwich Islands 25 
Mariannes 2, Ceylon 1. 
Pura, Lamarck. Chrysalis-shell. 
Type, P, mya. Pl, KL, Bie. 16: 
Synonym, Torquilla (juniperi), Studer. 
