History of British animals - University of Guam Marine Laboratory

MOLLUSCA. PULMONIFERA. 255PULMONIFERA.TERRICOLA.Tcntacida usually round, and Jourin number. The eggs arehatched on land.I. Limacid.e. Cloak and foot parallel, enclosingthe viscera.a.Pulmonary cavity placed near the head, covered by a thick shield.ArionLimax.aa.Pulmonary cavity near the tail, covered by a spiral open shell.Testacella.II. Cochleare. Cloak and foot not parallel; the viscera containedin a spiral,dorsal protuberance, protected bya shell.a. Foot with a lid for closing the mouth of the shell.Cyclostoma.Helecina.aa. Foot destitute of a lid.b. Helicidje. Last formed whorl larger than the penultimateone.c. Animal capable of retiring within the shell, the peristome ofwhich, with the exception of Achatina, becomes thick atmaturity.cc.d. Shell depressed or globose.dd.e. Peristome entire, raised on the pillar.Carocolla.ce.Peristome interrupted on the pillar.Helix.Shell turriteil.Bulimus.Achatina.Animal incapable of withdrawing within the aperture of theshell, the margin of which is thin.Succinea.Vitrina.bb. PuPADiE. Last formed whorl nearly of the same size as thecc.penult one, or even less, giving the shell a subcylindricalform.c. "Whorls dextralPupa.Azeca.Carychium.Whorls sinistral.Balea.Clausilia."Vertigo.