LAND AND FRESH-WATER MOLLUSCA OF GREENOCK. 281 
find a variety of Helix nemoralis with the shell 
slightly smaller than usual, semitransparent, and of 
a greenish-yellow colour; but after the animal has 
been killed the shell becomes opaque and of a more 
decided yellow colour. This variety—the only one I 
have noticed at that place—I do not find anywhere 
else in the district. At the “Moat-hill,” Cupar-Fife, 
I got an almost black variety of the same species. 
At that place most of the shells are of a blackish 
colour; but nowhere else in the neighbourhood 
ffl find them so dark, though I -have got 
them of a somewhat similar colour on the Castle- 
rock, Edinburgh. Again, at a place near Kenmore, 
Perthshire, I gathered some specimens of the same 
species, of a yellow eround-colour, with dark brown 
bands: but in adult specimens these bands became 
broken up and diffused over the ground-colour just 
‘before reaching the lip, thus producing a rather 
pleasing effect. This peculiar band-dispersion was 
not observed in specimens gathered from any other 
place in that locality. Accordingly, when variations, 
though only in colour, are met with, and appear to 
be strictly local, as in these examples, the reason for 
such restriction forms a subject of enquiry at once 
interesting and important. 
It will be seen from the List, which has been 
prepared for me by my son Andrew, that the 
aquatic species are but poorly represented in our 
district. With perhaps one or two exceptions, all 
those recorded are comparatively common, the reason 
being that there are few places suitable for the 
propagation of aquatic molluscs. One of the excep- 
tions I have mentioned is Pisidiwm nitidum. I find 
this species—along with other two interesting things, 
viz.: Candona euplectella (an ostracode) and Utricu- 
laria minor (a bladderwort)—in some pools by the 
side of the road leading from Port-Glasgow to 
Kilmalcolm. These pools occur in a natural hollow 
through which the road passes, and are probably 
all that remain of what was once a considerable 
