pbferved, they were not uncommon in the ditches about 

 Sundzuic/i. We have alfo found it, of a larger fize tharr 

 ufual, in a pond at Wedhampton in WilfJJiire, ^vith the 

 Helix alba. Diameter one eighth cf an inch. 



In a pond at Knowle, near Kingshridge in DevovJIiire, 

 it is in profufion ; thefe are of a light colour, with a 

 greenifh tinge, and rarely fpined ; but the ribs are fre- 

 quently very confpicuous, efpecially on the under part: 

 and in a ditch of running water, which occafionally flows 

 from the pond, they are equally abundant, of a dark 

 colour, and flrongly fpined along the dorfal fi3rz?ia; an 

 evident proof that this variety is occafioned by adventi- 

 tious circumftances, fuch as the nature of their food, 

 and quality of the water they inhabit. It is found on the 

 under fide of the leaves of many fub -aquatic plants, but 

 feems partial to the creeping Wxter-parfnep, Slum nodi- 

 Jlorum, and Water-crejfes, Sifymbrium Najlurtium. 



Animal of a pale colour ; tentacula two, fetaceous ; 

 eyes on the head, fituated at the bafe of the tentacula. 



GEN. 



