GASTEEOPODA. 165 



Listr. 650 sp. Europe 30, Asia 130, Australia and Pacific Ids. 46, 

 Africa 50, S. States 3, Tropical and S. American 330. 



Fossil. 30 sp. Eocene — . Europe, S. Helena, Australia, W. Indies. 

 B. Guadalupensis occurs in modern limestone, wdth human remains. 

 AcHATiNA, Lamarck. Agate-sheU. 



Tf/pe, A. variegata, PI. XII. fig. 22. 



Si/ti. Cochlitoma, Per. Columna, Perry. Subulina (octona) Beck. Li- 

 guus (virgineus) Montf. Cionella (acicula) Jeffr. 



Shell imperforate, bulimiform ; columella twisted, and truncated in front ; 

 aperture oval, angular above ; peristome simple, acute. 



Animal snail-like. The great African Achatinffi are the largest of all 

 land-snails, attaining a length of 8 inches ; their eggs exceed an inch in 

 length, and have a calcarious shell. 



Distr. 120 sp. Europe 9, Africa 38, Asia 8, tropical America 29. 



Fossil. 14 sp. Eocene — . Europe ; St. Helena. 



Suh-genera. Glandina (voluta) Schum. (Oleacina, Bolten; Polyphe- 

 mus, Montf.) Shell oblong, fusiform ; aperture narrow, elliptical. Animal 

 twice as long as the sheU ; eye tentacles deflected at the tips, beyond the eyes ; 

 vibracula much shorter, also deflected ; lips elongated, tentacular. Prequents 

 low and moist situations ; in confinement one refused vegetable food, but at 

 another snail. {Say) 40 sp. W. Indies, Central America, Mexico, Florida. 

 Fossil. Eocene — . Glandina costellaia. I. Wight. \F. Fdwards.) 



Achatinella (vulpina) Sw. (Helicteres, Per.) Columella twisted into a 

 strong, tooth-like fold. Sandwich Ids. 25, Mariannes 2, Ceylon 1. 

 Pupa., Lamarck. Chrysalis-shell. 



Type, P. uva. PI. XII. fig. 16. Syn. Torquilla (juniperi) Studer. 



Shell rimate or perforate, cylindrical or oblong ; aperture rounded, often 

 toothed ;* margins distant, mostly united by a callous lamina. 



Animal vnth a short foot, pointed behind ; lower tentacles short. 



Distr. 160 sp. Greenland 1, Europe 76, Africa 23, India 12, Pacific 

 Ids. 2, N. America 30, S. America 5. Fossil. 40 sp. Eocene — . Em-ope. 



Sub-genus. Vertigo, MuU. V. Venetzii. PI. XII. fig. 17. SheU mi- 

 nute, sometimes sinistral. Animal with the oral tentacles rudimentary or 

 obsolete. 12 sp. Old World. 



Cylindrella, L. Pfeiffer. Cylinder-snail. 

 Type, C. cylindrus. PI. XII. fig. 20.t 



Hdena ; from a specimen presented by Chas. Darwin, Esq. See " Journal of a Voyage 

 round the World." 



* Dr. Pfeiffer terms those teeth parietal which are situated on the body-whirl 

 those on the outer lip palatal, and on the inner lip columellar. 



+ The figure is taken from a sp. in Mr. Cuming's cabinet, in which the empty apex, 

 usually decollated, remains attached to the adult shell. 



