188 THE GASTROPODA 
Scopoli ; shell ovoid, with oval or elongated aperture and a thickened 
border. Hemphillia, Binney and Bland; shell unguiform, its edges 
covered by the mantle; North America. Berendtia, Crosse and Fischer. 
Cochlostyla, Férussac. thodea, Adams. Famity 8. ENDODONTIDAE, 
Pilsbry. Shell spiral, external, generally ornamented with ribs ; borders 
of the aperture thin and not reflected ; radula with square teeth ; genital 
ducts without accessory organs. Genera—Endodonta, Albers, Punctum, 
Morse. Sphyradiwm, Charpentier. Laoma, Gray. Pyramidula, Fitzinger. 
FamiLy 9. ORTHALICIDAE, Fischer. Shell external, ovoid, the last whorl 
swollen, the aperture oval, with a simple border ; radular teeth in oblique 
rows. Genus—Orthalicus, Beck ; American. FAMILY 10. BULIMULIDAE. 
Fischer ; jaw formed of folds imbricated externally and meeting at an 
acute angle near the base. Genera—Bulimulus, Leach ; shell elongated, 
oval, external. Peltella, Webb and van Beneden; shell auriform, in- 
ternal. Amphibulimus, Montfort. Faminry 11. CyLINDRELLIDAE, Fischer, 
Shell turriculated, with numerous whorls, the last whorl more or less 
detached. Genus—Cylindrella, Pfeiffer ; aperture circular, with reflected 
peristome ; summit commonly truncated ; America. Famity 12. PUPIDAE, 
Fleming. Shell external, with elongated spire and numerous whorls ; 
aperture generally narrow ; male genital duct without multifid vesicles. 
Genera— Pupa, Lamarck ; shell cylindrical, dextral with obtuse summit ; 
aperture parallel to the axis, small and contracted ; British. Hucalodiwm, 
Crosse and Fischer ; shell turriculated, the summit truncated, the aperture ~ 
oval. Vertigo, Miller ; shell small, ovoid, the summit obtuse, the aperture 
small and contracted by numerous teeth ; dextrally or sinistrally coiled ; 
a single pair of tentacles; British. Buliminus, Ehrenberg; shell 
umbilicated, ovoid, with elongated aperture and a simple columella ; 
British. Clausilia, Draparnaud ; shell turriculated, sinistral ; aperture 
oval; the columella with corrugations and a movable piece, the 
clausilium, by means of which the mouth of the shell can be closed ; 
British. Balea, Prideaux ; shell sinistral, differs from Clausilia in the 
absence of columellar corrugations and clausilium. Zospewm, Bourguignat ; 
no eyes, shell short and dextral. Megaspira, Lea. Strophia, Albers. 
Anostoma, Fischer. FaAmiIty 13. SrTENOGYRIDAE, Fischer. Shell elongated, 
with a more or less obtuse summit ; aperture oval with a simple border. 
Genera—Achatina, Lamarck ; shell ovoid, the spire conical, the last 
whorl ventricose ; the columella twisted. | Stenogyra, Shuttleworth ; shell 
turriculated ; the whorls numerous, increasing slowly (Fig. 8). Ferussacia, 
Risso; shell small, thin, and brilliant ; aperture elongate, oval ; British. 
Caecilianella, Férussac ; shell cylindrical, the spire elongated, the columella 
truncated ; eyes absent; subterranean in habit; British. Cionella, 
Jeffreys. Azeca, Leach. Opeas, Albers. Ehodea, Adams. Faminy 14. 
HELIcreRIDAR, Fischer. Shell bulimoid, dextral or sinistral; radular teeth 
narrow at their bases, expanded at their extremities and multicuspidate. 
Genera—Helicter, Férussac. Tornatellina, Beck. 
TRIBE 2. AGNATHA. 
No jaws; the radular teeth narrow and pointed ; carnivorous. This 
group is possibly polyphyletic. 
