LIMN^EA. 39 



both in size and form. I have some of the Var. corvus, 

 which I took in Essex, one and a half inches in length, 

 of a dark purple colour truly magnificent shells. 



Var. I. corvus. Larger, more tumid, dark purple. 



Var. II. elongata. Spire more produced. 



Var. III. tincta. Shorter and broader, mouth 

 purplish. 



Var. IV. conica. Conical, whitish, suture deep, 

 having an umbilical cleft. 



Var. V. roseo-labiata. With rose-coloured rib. 



Var. VI. decollata. Spire truncate. 



Var. VII. albida. White. 



7. L. TRUNCATULA (somewhat truncated). 



Somewhat resembling L. palustris in shape, bnt turreted 

 in appearance with deeper suture ; rather glossy ; mouth 

 ovate ; umbilical cleft distinct. 



This species is very liable to be confounded with 

 some variety of the last, which in general form it 

 somewhat resembles. It is, however, much smaller 

 and more elegant in shape, with a much deeper suture, 

 which gives it its turreted appearance, and more tumid 

 whorls. 



It is common both in still and running water, espe- 

 cially in shallow pools, which are often dried up in 



