38 
MOLLUSCA. 
Shell with from ten to twelve reversed, smooth, glossy, pel- 
lucid volutions, of a reddish horn-colour ; body volution very 
small ; spire very long ; the volutions thickening towards the 
middle, and tapering from thence to a small, somewhat obtuse, 
and rounded point; each of the volutions swelling a little in 
the centre, and the whole well defined by the suture line ; 
aperture suborbicular, compressed, thickened, and white at the 
upper outer margin, where it unites with the body ; outer lip 
white, slightly marginated and reflexed, with two laminar plaits 
or folds, one of which is straight, situate near the superior 
portion of the aperture, and nearly central, the other somewhat 
curved, placed in the middle of the pillar lip, and frequently 
crenated ; deep within the aperture are situate three or four 
prominent ridges, which are discernible when held up betwixt 
the observer and the light. General length three-quarters of 
an inch ; diameter, one-fourth of its length ; the clausium is 
emarginate. 
This species is subject to some variation in colour and dia- 
meter; some specimens being of a greenish-yellow, while others 
are more ventricose in the centre ; it also diflfers a little in 
length. 
The favourite resort of this species is a calcareous soil ; it 
is to be met with in woods of beech trees, and has been found 
at Bow Wood, the seat of the Marquis of Lansdowne, Lack- 
ham Wood, Wiltshire; and I found it, of a large size, on the 
bark of a decayed tree at Hexham; and at Dove Dale, Derby- 
shire, by William Thompson, Esq. It has been found at 
Belamont Forest, near Coothill, County of Cavan, Ireland, by 
my friend T. W. Warren, Esq., of Dublin, and on trees, in 
the demesne of Florence Court, County of Fermanagh, by that 
able conchologist, William Thompson, Esq., of Cork. 
This is a very local species, and certainly the most beautiful 
of our native Clausilice. 
Section II. — Shells corrugated; and with the clausium 
entire at the top. 
2. Clausilia biplicata, pi. XIV, f. 13. — First Ed., pi. 
41, f. 13. 
Clausilia hiplicata, Leach, Moll., p. 120; Alder, Mag. Zool. 
and Bot., II, p. 110; Fleming, Brit. An., p. 271; Turton, 
Man., p. 72, f. 55 ; Clausilia Montagui, Gray, Ann. Phil., p. 
13; Clausilia verrucosa, Drapernaud, Hist, des Moll., p. 71> 
pi. 4, f. 11 ; Pfeiffer, p. 63, pi. 3, f. 29; Jeffreys, Linn. Tr., 
XVI, p. 354; Clausilia similis, Rossmassler, Icon., p. 177, pi. 
2, f. 30; Turbo biplicatus, Montagu, Test. Brit., p. 361, pi. 11, 
f. 5; Helix perversa, adult, Muller, Verm., H, p. 118; Helix 
cocholodina ventricosula, Ferussac, pi. 63. 
Shell opaque grayish-brown; with twelve or thirteen reversed 
volutions ; whole surface covered with numerous, longitudinal, 
strong, regular, slightly oblique striae; volutions well defined by 
the sutural line, which is rather deep, and terminating in a 
somewhat blunted apex; aperture suborbicular, rounded below, 
considerably compressed above, and a little sinuous at the upper 
and inner angle; provided internally with two plaits, one situate 
near the top of the pillar lip, and the other about half way 
down the base of the columella, their points approximating to 
each other as they recede inwardly ; lips thick, white, and con- 
tinuous and detached all round. 
[Trachelipoda 
This species is distinguished from C. bidens by its colour, 
superior size, and particularly in the shape of the aperture, the 
margins of which are reflexed and produced, and the teeth are 
much closer together in proportion to the size of the shell. 
First identified as a British species by Colonel Montagu, who 
discovered it at Easton Grey, Wiltshire, and has been found in 
Hyde Park, London. Its chief habitation is in woods and 
close-set hedges. 
3. Clausilia rugosa, pi. XIV, f. 14. — First Ed., pi. 41, 
f. 14. 
Clausilia rugosa, Drapernaud, Hist, des Moll., p. 73, pi. 4, 
f. 19j 20; Pfeiffer, p. 63, pi. 3, f. 30; Leach, Moll., p. 121 ; 
Turton, Man., p. 74, f. 58 ; Alder, Mag. Zool. and Bot., H, p. 
Ill; Clausilia perversa, Fleming, Brit. An., p. 271; Clausilia 
nigricans, Jeffreys, Linn. Tr., XVI, p. 351; Thompson, Ann. 
and Mag. Nat. Hist., VI, p. 42 ; Clausilia parvida, Leach, 
MSS.; Turton, Zool. Journ., H, p. 556; Ib., Man., p. 74, f. 
58 ; Jeffreys, Linn. Tr., XVI, p. 352 ; Turbo nigricans, Dill- 
wyn. Cat., p. 375 ; Turbo perversus. Pennant, Brit. Zool., IV, 
p. 130, pi. 82, f. 116; Turbo bidens, Montagu, Test. Brit., p. 
357, pi. 11, f. 7; Brown, Ency. Brit., 6th Ed., VI, p. 556; 
Helix perversa, Muller, Verm., p. 118; Brown, Wernerian 
Mem., H, p. 523. 
Variety 1. Shell smaller, and more slender in form. 
Variety 2. Shell shorter, with fewer volutions. 
Clausilia Everetti, Ann. Phil., N. series, XIX, p. 377. 
Shell somewhat opaque, blackish or chocolate-brown, fre- 
quently with ash-coloured or whitish longitudinal streaks, 
slender; with about twelve volutions, slightly inflated in the 
middle, and covered with elevated, granular, longitudinal strise ; 
aperture oval, the inner lip a little contracted, the columella 
provided with three plaits, the lower one placed interiorly, 
and scarcely discernible in the adult shell ; lips thick, detached 
from the body, and pure white. Length generally about half 
an inch. 
This is the most common species of Clausilia; inhabiting 
rocky or woody situations; it is subject to great variety in size, 
and even diameter. 
The Clausilia 2 iO‘^'vula of Dr. Turton’s Land and Fresh 
Water Shells, is only a variety of this species. 
4. Clausilia Rolphii, pi. XVIH, f. 31. 
Clausilia Rolphii, Leach, MSS.; Ib., Mollusc, ined., p. 119; 
Ferussac, Journ. Phys., 1820, p. 301; Alder, Mag. Zool. and 
Bot., II, p. Ill; Turton, Man., p. 71, f. 54; Clausilia Iphi- 
genia Rolphii, Gray, Med. Rep., 1821, p. 182; Ib., Ann. Phil., 
p. 15;' Turton, Man., p. 71, f. 54; Clausilia plicatula, Draper- 
naud, Hist, des Moll., p. 74, pi. 4, f. 17, 18; Rossmassler, Icon., 
p. 39, ph 2, f. 32; Jeffreys, Linn. Tr., XVI, p. 353 ; Brard, p. 
85, pi. 3, f. 10. 
Shell thin, opaque, ventricose in the middle, of a grayish- 
brown horn-colour ; body very short ; spire very long, consist- 
in" of nine or ten rather narrow volutions, each of which are 
somewhat inflated in the centre, and terminating in an obtuse 
apex ; the whole surface covered with close-set, elevated, lon- 
gitudinal striae; aperture subovate, sinuous at the outer and 
upper angles ; outer and inner lips white, thick, and detached 
all round ; provided with four or five plaits on the columellar, 
two of which are longer than the others. 
