CLASSES, ORDERS, ETC. 77 



tr.actile, cylindrical, the upper pair being the longest and bearing 

 the eyes at their apices. 



15. Succinea. Shell oval or oblong, thin, transparent; spire 

 short ; mouth large and obliquely oval ; non-operculated. Animal 

 not capable of entirely entering its shell. 



(a) Shell, ovate, oblong, smooth, glossy, amber-coloured, trans- 



Fig 31. Succinea putris. 



parent ; whorls three to four, ventricose, the body- whorl occupy- 

 ing |ths the length of the shell ; mouth ovate, two-thirds the length 

 of the shell. Length \ to f ths inch. On the banks of ditches and 

 streams on flags and willows. Moderately common. 



S. putris.^ 



(b) Shell oblong, suboval, thin, greenish-yellow, transparent ;. 

 spire very short ; mouth ovate. Length f ths inch. Marshes and 

 ditch-banks. Moderately rare. 



S. virescens. (= Succinea putris var. vitrea.) 



(c) Shell amber-coloured, semi-transparent ; compared with that 

 of S. putris it is smaller, more slender, with a longer and more 

 pointed spire ; the suture near the mouth is also much deeper.. 

 Length \ inch. Marshes and ditch-banks. Moderately common.. 



S. elegans.^ 



(d) Shell oval, elongated, pale yellow or reddish, transparent^ 

 whorls three, twisted, the body-whorl occupying near the whole 

 of the shell ; spire short, with the apex tuberculous ; suture oblique,, 

 well defined but not deep ; mouth an elongated oval, about f rds 



48 v. yubglobosa, shorter, broader, smaller, more solid ; V. solidula, reddish- 

 yellow, much thicker; v. Ferussina, deep reddish-fawn coloured, small, 

 slightly elongated. 



49 v. albida, white ; v. minor, thinner, reddish-brown, spire shorter, aperture 

 more expanded ; v. ochracea, thicker, smaller, spire longer, aperture smaller. 



