PROCEEDINGS OF SOCIETIES. 
87 
Planorbis marginatus. Very abundant, of the common form; some with a very 
slight line indicating the keel, and a few without any trace of it. Plan¬ 
orbis carinatus is found in the marl, and is the only marl shell which 
I have not found living in the district. 
„ vortex. Abundant; rarely with the white rib inside the mouth. 
„ spirorbis. Abundant; occasionally is seen with the white rib within 
the mouth. 
„ nitidus. Rare ; in one pond, at Pinnoe. 
,, contortus. Very abundant. 
Cyclas cornea. Abundant; varying considerably in globosity and size. 
Pisidium obtusale. Rare and local. 
„ nitidum. Not uncommon. 
,, pusillum. Abundant. 
,, pulchellum. Common. 
,, Henslowianum. Very rare and local. I obtained a very few specimens, 
in drains, near the river, now dried up. The shells scarcely exceeded 
one-eighth of an inch in length, and the laminar projections were not as 
prominent as they are represented in Mr, Jenyns’s monograph. All 
these small Pisidia were determined by my friend, the late Mr. William 
Thompson, from shells sent to him, to Belfast. I found shells of all 
the species agreeing, pretty accurately, with the typical figures and 
descriptions of Jenyns ; some belonging to his varieties, and some not 
easily reducible to them. 
,, amnicum. Rare and local. 
This small district thus possesses 66 of the 96 species recognised by Mr. William 
Thompson, in his Catalogue (Ann. and Mag. Nat. Hist. VI., p. 16, Sept. 1840), as 
being Irish. I might, perhaps, have added Li max flavus, Helix hybrida, Helix 
hortensis, and Helix sericea; but I would not introduce any species I was not per¬ 
fectly certain of. It will be seen, that I obtained several additional species, at 
Finnoe, since 1840, by reference to Mr. Thompson’s Catalogue, under the head of 
Finnoe. 
My observations on these mollusca lead me to think that some zealous investi¬ 
gators of this branch of zoology, from the very natural desire of making its arrange¬ 
ment as accurate and minute as possible, have unnecessarily multiplied species 
which, independent of the error, much embarrasses those studying either the shells 
themselves, or the works written on them. 
Dr. Lyon Playfair considered that such lists, from various localities, would be 
very valuable. 
Professor Allman urged the necessity of local lists, this being the true way to 
arrive at the knowledge of geographical distribution, and that such knowledge 
would ultimately be of beneficial results. 
Mr. J. R. Kinahan then exhibited specimens of a bat, taken in the County 
Kildare, and gave the following reasons for considering it to be a distinct species 
from the Vespertilio pipistrellus:—1st. The hairy fringe on the interf'emoral. 2nd. 
The greater number of false molars in Natterer’s bat. 3rd. The difference in shape 
of the trajus; in Natterer’s bat long and pointed, in the pipistrelle short, and 
rounded at its extremity. 4th. The different colours ; Natterer’s bat being dark- 
greyish red on the back, silvery white on the belly ; while the pipistrelle is a uni¬ 
form light gray. 
Mr. Kinahan, while referring these specimens for the present to Natterer’s bat, 
pointed out differences between them and the description in Bell’s British Quad¬ 
rupeds, and also the specimen of this bat killed at the Scalp, in 1849. These 
were:—1st. The non-development, to any extent, of the sebaceous follicles of the 
nose. 2nd. The greater number of interfemoral nervous bands (a character which 
differs in almost all Mr. Kinahan’s specimens). 3rd. The shortness of the spur 
of the heel. 4. The fringe being continued beyond the hind paw, half-way up to 
the last finger. 5th. The comparative shortness of the trajus. 
The President did not consider this bat to be V. nattereri; it did not agree with 
that species as described by Demarest, or Baron de Sely’s Longchamps. Its most 
