246 THE ZOOLOGIST. 
to be upon the grassy bank against the outside of the city walls 
opposite the entrance to the new station. Here I chanced to 
observe an individual of this species scaling the walls. A search 
soon showed me that in the roots of the grass below my feet they 
were swarming, and to such an extent that in one particularly 
favoured spot, certainly not larger than one square yard, Ij ob- 
tained no less than sixty-four live specimens. Of course this was 
exceptional, but they teemed over the whole bank, particularly near 
the top, where they actually crunched beneath my feet as I walked. 
On looking around one had not far to seek for the cause of this 
unusual abundance in a limited space. At the bottom of the 
bank runs a much-used road with the station on the other side of 
it; at the top are the city walls, which they do not seem to have 
crossed, as I could find none upon the corresponding bank on the 
other side, while at one end is the River Ouse, and at the other a 
broad railway-line. Doubtless the impossibility of migration 
accounts for the congregation. ‘The raids made upon them by 
the collectors from Bootham and elsewhere soon caused a thinning 
of their numbers, both because of those carried away and the 
trampling down of the nettles, which exposed them to the attacks 
of either rats or thrushes. At any rate, many recently emptied 
shells were soon strewn about. Some were of large size, but as 
a rule they were small. 
Var. albida.—Quite one-sixth of the entire lot were of this 
variety. 
Var. flavescens.—In the same proportion as the last-named. 
One cannot suppose that so many living together can have had a 
beneficial effect upon them, and their small size and lack of 
colouring, which the abundance of these varieties show, is thus 
accounted for. Fulford (H.) 
Var. conoidea.— One at Castle Howard and a few by the walls. 
Helix cantiana.— Very abundant. Young individuals are 
whitish and hispid. Common over the whole district, especially 
near Dringhouses and the whole way between York and Dun- 
nington. 
Var. albida.—I have taken a few near Dunnington. 
Helix rufescens.—Very scarce near the city. I have never taken 
it here myself. The ‘ Observer’ states it to have been found both 
at Skelton and on nettles near Holgate. It occurs under stones 
near Clifton, but is very scarce (H.) It is, however, common on 
