94 
PROCEEDINGS OF SOCIETIES. 
Zonites rotundatus. Abundant everywhere. 
„ alliarius. Not uncommon. 
,, cellarius, Occasionally found. 
,, nitidulus. Common. 
Succinea putris. Rather plentiful; I have taken remarkably fine specimens on the 
bank of the Dodder, at Firhouse. 
,, Pfeifferi var. I believe this occurs occasionally with the last species ; 
but I am inclined to think that it is not really distinct from it. 
Bulimus obscurus. Dundrum, &c.; not unusual. 
„ acutus. Abundant; principally on the sea-coast. 
Zua. lubrica. Very common. 
Pupa umbilicata. Generally distributed. 
,, marginata. Frequent, along with umbilicata; unless this be the toothless 
variety of that species alluded to by Mr. Waller, in his paper on the 
Finnoe mollusks. Gray mentions a toothless variety of marignata only, not 
of umbilicata. 
Vertigo pygmsea. Mount Merrion; one specimen. 
,, alpestris. Same locality; not more plentiful. 
Balasa perversa. Abundant about Roebuck, both on walls and trees ; among the 
latter I have found it chiefly on the elm. 
Clausilia nigricans. Generally distributed ; often on old walls. 
Limnseus pereger. Abundant in all its ordinary haunts. 
,, stagnalis. Ponds in Glasnevin Botanic Gardens. 
,, palustris. Ditches at Rathmines; the specimens of unusually large size. 
„ truncatulus. Scarce ; at least not generally distributed. My specimens 
were taken at Charlton, the most distinct of them being peculiar to an old 
water-cask standing in a garden, but unfortunately removed since, 
to the destruction of the flourishing colony. 
Ancylus fluviatilis. In a small stream at Rathfarnham. 
Physa fontinalis. Rare; I have only found dead specimens. 
Aplexus hypnorum. Local; but very abundant about Roebuck, and usually in 
clear, running streams, which would appear to be different from the experience of 
English collectors, as the locality given by Gray is u ponds and slow streams.” 
If one might j udge from the conformation of the shell, it seems peculiarly adapted 
to the former. 
Planorbis carinatus. Glasnevin Botanic Gardens, I believe. 
,, marginatus. Common. 
„ vortex. In a ditch at Donnybrook. 
,, spirorbis. Glasnevin, as well as I can recollect. 
„ contortus. Two dead specimens at Charlton. 
Cylas cornea. Common. 
Pisidium pulchellum. A single specimen at Celbridge, on the bank of the Liffey. 
I have also taken one or two other species of Pisidium (one of them being am- 
nicum) near Dublin; but have, unfortunately, allowed them to become mixed 
with specimens from other places. 
Mr. W. Walpole mentioned that Baltea perversa had not been, in his expe¬ 
rience, found in the locality stated by Mr. Hogan—namely, the elm ; but was 
common on the beech. 
Mr. Kinahan exhibited a lengthened series of specimens of H. nemoralis and 
hortensis, and hybrida, and made several observations on these varieties, the two first 
of which, at least, he looked on as species, owing to differences which he had found 
permanently pervading each in every locality where they were found. 
Mr. Hogan considered that the depression of the spire was the principal dis¬ 
tinctive mark of Helix hybrida. 
The President observed that there was here a subject for philosophical inquiry ; 
and urged that to malacology, rather than conchology, we should look for a solution 
of the difficulty. He then exhibited from his old collection some specimens which he 
considered typical of the species nemoralis and hortensis, some remarkable forms 
of the former, as well as unusual varieties of Helix aspersa. The meeting then 
adjourned. 
