l^O HYALINIA GLABRA IN NORTHAjMPTONSHIRli. 



Had the shells come from Norway, Sweden, or Prussia, it 

 is likely that it would have been discovered ere now by some of 

 the keen investigators of those countries, but it is not so likely 

 that conchologists have wandered along the low-lying shores of 

 Russia and Finland^ which shores, from personal knowledge, I 

 can testify to being extremely desolate. 



It may be remembered that the habitat of P. jenkinsi is 

 slightly brackish dykes, such as timber is likely to be stored in 

 while awaiting shipment. 



In all the three known localities the water is usually fresh 

 and from one to three miles from the sea. x\t .Sandwich the 

 shell was associated with Sphcerium corneiun and Valvata 

 piscinaiis ; the water was then fresh, but possibly at high tides 

 the salt water of the tidal Stour may get into the dyke through 

 the sluices which I observed. 



At Countess Weir it occurs in a small brook which runs 

 into the Exe, whither salt water percolates, though not to any 

 extent, and Pisidiiini fontinale, Planorbis alluis, P. conio/ius, 

 Liiiuicea peregra,''' and Z. truncahda were associated with it 

 among the Anacharis weed, which was plentiful. 



I have had the curiosity to go through 1256 specimens 

 from Topsham to find the approximate ratio of the carinated 

 to the uncarinated forms ; I find only 9^- per cent, are un- 

 carinated. 



L. fcreg^ra is well known to exist and thrive in brackish water, and I have found PI. 

 vortex and PL spirori'i's in a \ery salt marsh at Dovercourt, near Harwich. 



Hyalinia glabra in Northamptonshire. — In Mr. 



W. D. Crick's carefully-compiled ' List of the MoUusca of 

 Northamptonshire,' vol. iv., p. 247, attention is called to the 

 absence of IP. glabra amongst other species. I have been 

 fortunate enough to find two live specimens, and also one of 

 the viriditla form of H. aUiaria, which is also omitted in the 

 list, at Bratfield, near Northampton. — L. E. Adams, Ja)i. 22, 

 1893. 



J.C. . vii. , Jan. 1893. 



