CONOVULUS. 191 



(p. 219. f. 1, 2. Montagu, T. B. 340. ; Sturm, t. 1. 

 f.3.) 



Shell hardly the tenth of an inch long, conic, 

 white, shining, with a yellowish cast, transparent ; 

 spire composed of five rounded volutions, very finely 

 striate longitudinally, and ending rather obtusely ; 

 aperture semioval or rather ear-shaped, rounded at 

 both the ends, with two teeth on the pillar, and some- 

 times a small one above the others; the margin 

 thick, and in the middle of the outer lip a thick 

 tooth-like protuberance. 



2. CONOVULUS. (Conovulus.) 



Shell oval, obconic ; last whorl long, compressed ; 



mouth linear; pillar with two or three spiral 



plaits ; outer lip simple or very slightly reflexed ; 



throat grooved. 



The foot of the animal is obovate, oblong, blunt 



in front and behind ; tentacles Fig. 46. 



contractile, filiform, slightly 



ringed ; eyes at their inner 



base ; muzzle porrect, notched 



in front, as in Limnceus ; mantle 



closed all round, with the excep- 

 tion of a perforation at the point 



of junction of the outer and Conovulus denticulate. 



inner lip. The pillar of the shell is plaited in all 





The animal, in habit, manner, and appearance, 

 very greatly resembles that of Aplexa or Limnaus, 

 but differs in the tentacles being filiform and ringed. 



