38 



MOLLUSCA. 



[TRAC'HELII'ODA 



Shell with from ten tu 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 differs 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 Row 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 biplicata, 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. 

 1 3 ; Clausilia verrucosa, Drapernaud, Hist, des Moll., p. 7 1 , 

 pi. 4, f. 11 ; Pfeiffer, p. G3, 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. 3G1, pi. 1 1, 

 f. 5; Helix perversa, adult, Miillcr, Verm., II, 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. 



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. 19, 20; Pfeiffer, p. 63, pi. 3, f. 30; Leach, Moll., p. 121 ; 

 Turton, Man., p. 74, f. 58 ; Alder, Mag. Zool. and Bot., II, 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 parvula, Leach, 

 MSS. ; Turton, Zool. Journ., II, p. 556 ; lb., 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., II, p. 523. 



Variety 1. Shell smaller, and more slender inform. 



Variety 2. Shell shorter, with fewer volutions. 



Clausilia Everetli, 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 stria; ; 

 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 parvula of Dr. Turton's Land and Fresh 

 Water Shells, is only a variety of this species. 



4. Clausilia Rolphii, pi. XVIII, f. 31. 



Clausilia Rolphii, Leach, MSS.; lb., 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; lb., 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, pi. 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- 

 ing 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 stria;; 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. 



