294 
MOLLUSCA. 
shell of this species, marked “ H. revelata , Belfast,” and as presented by 
M. Michaud ; it is doubtless one of a series of specimens, which, consider- 
ing them to be H. ericetorum, I had the pleasure of sending to this na- 
turalist some time before. 
Mr. O’Kelly of Dublin, to whom the shell belongs that was described 
and figured by Capt. Brown in the W ernerian Memoirs as Helix elegans, 
and in his “ Illustrations,” &c., as Carocolla elegans, always considered it 
as an extraordinary state only of H. ericetorum , and as such noticed it in 
the Dublin edition of Pennant’s Brit. Zool., vol. iv. p. 368, ed. 1818. To 
the same specimen Dr. Turton applied the term Helix disjuncta , Conch. 
Diet. p. 61, f. 63 ; in his Manual (p. 40) this author places it under H. 
virgata. See also Gray, Man. p. 161. 
H. rotundata, Mull. 
This very distinct and handsome species, both in form and colour, is 
common and universally distributed in Ireland. It affects situations 
varying from very dry to very wet, and may be found on rocks, under 
stones, fallen leaves, & c., but seems rather to show a predilection for de- 
caying wood. I have more than once detected the H. rotundata in com- 
pany with Limaces banqueting on some of the larger Fungi. 
Specimens presenting much convexity are unfrequent, but in Shane’s 
Castle Park (County Antrim) a full-grown one has occurred to me, whose 
height was equal to its diameter. At Holywood House (County Down) 
I once obtained two specimens of the beautiful crystalline variety. The 
young of this species differ very much in form from the adult, in being 
quite flat above and very convex beneath. In the stomach of a black- 
bird ( Turdus Merula ) I once found ten full-sized specimens of this shell, 
in addition to five of Achatina lubrica. 
H. umbilicata, Mont., 
Is commonly distributed throughout the southern three-fourths of Ire- 
land, more especially over the great limestone belt which traverses the 
country : — at its eastern commencement, near Dublin, and at its extreme 
western verge, where it dips into the ocean, in the South Islands of Arran, 
I have found this species in equal abundance. — Glenarm and Garron Point, 
1842. W. T., Scrabo, Co. Down, 1843. 
This Helix attaches itself more to one kind of rock — limestone — than 
any species hitherto treated of. With reference to what Montagu says of 
its habits, it may be remarked that I have commonly collected specimens 
on limestone debris resting on the ground, and on loose stone walls or 
dykes. I have not seen any Irish specimens agreeing with Draparnaud’s 
figure in tapering to the apex ; but all were of his var., “/3. testa subde- 
pressa, umbilico latiore.” Mr. Gray’s figure, as above quoted, is charac- 
teristic of this form ; in the 1st ed. of Turton’s Manual the other form was 
given. It is Drap. var. (3. only that Mr. Jeffreys quotes (Linn. Trans, 
vol. xvi. p. 343), and it is this which Montagu describes ; his figure does 
not well represent either form. 
H. pygmcea, Drap. 
This species, so interesting from its minuteness, is indigenous to the 
more northern two-thirds of Ireland from East to West, and doubtless will 
be found by him who searches properly for it in the South. It is partial 
to shade and moisture ; under stones in pastures it may be procured, but is 
most readily and frequently obtained on fallen leaves, &c., in plantations. 
Since the Mollusca first claimed my attention in 1832, this Helix has 
