10 PALUDINID^.. 



which contrasts strongly ^vith the swelling roundness of the 

 base of the preceding volution. The body, viewed dorsally, 

 slightly exceeds the length of the spire ; the base is 

 rounded, rather short, and distinctly umbilicated. The 

 mouth, which is obliquely rounded-oval, and projects con- 

 siderably from the axis, occupies three-sevenths of the 

 total length, and more than half of the basal diameter ; the 

 peristome is acute, simple, and of a brownish black. The 

 outer lip is well rounded and not effuse in front, the inner 

 one is very little reflected. Large individuals measure an 

 inch and a quarter in length, and not much more than a fifth 

 less in breadth. The young, according to Mr. Gray, are 

 subglobose, pellucid, and furnished with five ciliated lines. 



The animal is greyish or blackish brown tinged with 

 orange and marked with brilliant yellow specks. Its head 

 has a long rounded muzzle cloven at the extremity ; the 

 tentacula are long and subulate with thickened bases formed 

 out of the eye-peduncles united with them externally, and 

 bearing the eyes on their prominent projections ; the right 

 tentacle of the males is shorter than the left, and thick- 

 ened at its extremity. Foot angulated in front, rounded 

 behind. Mantle very lax and ample. The creature, when 

 walking, displays itself freely, but is at times very sluggish 

 when in confinement. 



In Britain this species is chiefly confined to the southern 

 half of England ; it is reported, however, to occur at 

 Southport in Lancashire (Brown). Mr. Bean takes it 

 near York. It inhabits slow running rivers and canals, 

 and is common in the Thames district. It is found 

 in the Trent. Mr. Clark finds it in the river Ex, and 

 Mr. Jeffreys in the rejectamenta of the river Tawe, at 

 Swansea. A greenish white variety, without bands, has 

 been found by Mr. Pickering in the river Lea, Herts ; 



