34 LIMNJEID^E. 



This pretty little shell is found in ponds and ditches 

 widely distributed, but it is said to be local. It 

 forms an attractive object in an aquarium as it floats 

 on the top of the water with its dark blue foot upper- 

 most. 



2. P. FONTINALIS (frequenting springs). 



Sinistral, oval, very thin, glossy, semi-transparent, 

 greenish horn-colour ; whorls four to five, tumid ; spire very 

 short, but pointed obtusely. 



This shell, which is very common in running water 

 and ponds on weed, is often disappointing when the 

 animal is removed. When wet with the animal inside 

 the shell appears iridescent, but when clean and dry 

 is often dull. 



This species is perhaps more interesting as an 

 inmate of an aquarium than the last, as it is un- 

 usually active for a mollusk, and amusingly quarrel- 

 some. When two individuals meet, they engage in 

 (seemingly) angry combat, jerking themselves and 

 their antagonist to and fro like wrestlers ! They spin 

 colourless threads of mucus, along which they crawl 

 and practise gymnastics. 



Var. I. inflata. Much larger. 



Yar. II. curia. Spire very short. 



Var. III. oblonga. Spire produced. 



