334* SHELLS AND SHELL-FISH. 



SuB-FAM. 4. ACHATIN^. 



Shell spiral ; aperture oblong or oval, always equal, and 

 generally shorter than the spire.* 



Clausilia Drap. Aperture oblong, with teeth on both 

 sides t ; shell cylindrical. 



Pupella Sw. :|: Spire moderate, obtuse ; the whorls of 

 equal thickness ; basal whorl and aperture small ; 

 the latter with teeth on both sides ; the lips not 

 thickened. 



frumentum, Drap. 3.f.51,52. vertigo. Bow. Conch. 8. 

 variabilis. lb. f. 55, 56. f. 35. 



Eruca Sw. General habit of the last ; but the tip of 

 the spire is thicker, and there is only one, or no 

 plate, upon the inner lip only. 



muscorum. Drap. 3. f. 36-38. dolium. Drap. 3. f. 43. 

 fragilis. Tb. 4. f. 4. umbilicata. lb. 3. f. 39,'40. 



Balia Gray. Spire very long, of numerous persistent 

 whorls ; aperture simple, without teeth or folds. 

 B. fragilis. Drap. pi. iv. ventricosa. Zool. Journ. i. pi. 

 f. 4. 5, 6. 



Clausilia Drap. Spire very long, but the upper portion 

 deciduous ; aperture oblong, ear-shaped, with teeth 

 on both sides ; the lips united, and their edges 



• spreading. 



papillaris. Drap. 4. f. 13. plicatula. lb. 4. f. 17, 18. 



Macrodontes Sw. Size larger; bulimiform ; spire longer 

 than the aperture, which is surrounded with large 

 teeth ; lips united ; the outer large, dilated, and the 

 edge reflected. Tropical America only. 



M. Sowerbeyii Sw. Zool. Journ. i. pi. 5. f. 2. 



2. BuLiMus. Basal whorl ventricose ; outer lip mar- 



* Except in HeUcina and the turbinated Cydostomce. 



f Except in Balia, which has no teeth. 



% Including the European Pupce, Vertigo, and Alee. 



