146 
PROCEEDINGS COTTESWOLD CLUB 
1919 
further search was made, but the form apparently had migrated, 
only one specimen being taken. 
Planorbis crista var. laevigata, Adami. This shell was 
abundant in a small pond near lower Tuffley in the spring of 
1918. The type-form was also very common in several small 
ponds in the neighbourhood. 
physid;e. 
Physa heterostropha, Say. This interesting American 
species has extended farther up the canal. I have 
found it at Hempstead Bridge, and have little doubt that it 
would be found as far up as the Docks, but it has not been 
practicable to search above the bridge owing to war-time 
restrictions. During the autumn of 1919 I took it at Sharpness 
in much greater numbers and larger than ever before. 
CYRENID#:. 
Sphserium rivicola var. flavescens, Moquin-Tandon. 
In the early summer of 1918 this variety was found to be very 
abundant in the canal near Hempstead Bridge, most of the 
shells being of a brilliant yellow colour. 
Sphaerium pallidum, Gray, appears to have either 
migrated or died out at its old locality at Sharpness, as during 
the past summer I have taken nothing but dead valves ; not 
a single living specimen. 
Pisidium obtusale, Pfeiffer. This species has been taken 
in considerable numbers in two ponds on Podsmead Farm, 
Gloucester. 
