CLASSES, ORDERS, ETC. 69 



8. Bullinus. Shell spiral, thin, polished ; spire sinistral, non- 

 operculated ; columellar lip with a fold. Animal with two long 

 tentacles, with the eyes at their base ; mantle not capable of being 

 reflected on the shell, and destitute of lobes. 



(a) Shell fusiform, thin, yellowish or reddish-horn coloured, 

 glossy, semi-transparent; whorls six to seven, rounded; suture 

 shallow ; mouth oval-lanceolate. Length 1 to fths inch Ponds, 

 ditches, and slow-running streams. More or less local. 



B. hypnorum! 1 



9. Physa. Like Bullinus, but the columellar lip is without 

 a fold, and the mantle is lobed and capable of being reflected over 

 the shell. 



(a] Shell oval, thin, glossy, semi-transparent, pale greyish-horn 

 coloured ; whorls four to five, tumid, the last one occupying fths or 

 |ths of the shell ; suture deep ; mouth oblong and wider and larger in 

 proportion than in B. hypnorum. Length \ inch. Running brooks, 

 canals, ditches, and sluggish rivers. Common. P. fontinalis. 



(b] Shell an elongated ovoid, ventricose, glossy, finely striated 

 longitudinally, light horny or whitish in colour; whorls three, 

 the last one fths of the total height of the shell ; suture moderately 

 deep ; apex sharp ; mouth obliquely and narrowly oval, acute 

 above. Height |rd to -frds inch. In one of the lily tanks in 

 Kew Gardens; also in Botanical Gardens, Regents Park. Im- 

 ported. P. acuta. 



(c] Shell subovate, yellowish chestnut or blackish ; whorls four, 

 the last large ; apex acute ; aperture large, somewhat oval, three- 

 fourths the length of the shell, lustrous inside; lip thickened 

 internally and tinged dull red. Length ifths inch. Near Bath 

 and Birmingham. P. heterostropha. 



10. Amphipeplea. Shell thin, hyaline, ventricose; spire 

 depressed ; aperture wide with the inner lip expanded over the 

 last whorl. Mantle capable of being reflected over the shell. 



29 v. cuprella, copper-coloured, whorls six, convex, the last one far exceeding 

 in size the rest put together, mouth oval, contracted above ; v. major, larger, 

 more coloured, height 10 to 13 mm. ; m. decollatum, spire decollated. 



30 v. albina, milk-white ; v. oblonga, spire considerably produced ; v. inflata, 

 larger, more ventricose ; v. curia, spire extremely short ; m. dextrorsum, spire 

 dextral. 



