119 



Gulnaria lacustris. Leach, Mollusc, p. 146. 



e. with the outer lip much expanded, Linn. 

 Trans, viii. t. 5./. 8*. 



Shell varying much in size, of a greyish or yellowish 

 colour, and generally covered with a dark foul 

 crust, more or less striate : spire moderately elon- 

 gated, about a third part the length of the whole 

 shell, with the lesser volutions not so abruptly 

 disproportionate to the body one as in the last : 

 aperture oval-oblong with the umbilicus sometimes 

 obliterated. 



All these varieties run so much into each other, that 

 they can hardly be considered as specifically di- 

 stinct. The grooved variety d. we have been 

 able to trace in every degree of distinctness and 

 strength of the striae, a circumstance to which many 

 of this family are subject, more especially in the 

 L. glutinosus and L.fossarms. 



102. LIMNEUS Scaturiginum. Shell oblong, pellucid, 

 smooth, with a short obtuse spire : aperture narrow 

 oblong. 



Physa Scaturiginum. Drap. p. 56. t. 3.f. 14, 15. 

 Shell not half a line long, extremely thin and brittle, 



