COLIMACEA. 41 



Great Britain and Ireland, and tlie surrounding islands. Mr. 

 Thompson mentions a specimen found by him near Belfast, 

 which measures seven and a half lines in length, and is fur- 

 nished with thirteen volutions; and several others six lines long, 

 which have likewise the same number of volutions. 



The Clausilia parvula of Dr. Turton's Land and Fresh 

 Water Shells, is only a variety of this species. 



4. Clausilia Rolphii, pi. IV, f. 39, 40. 



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; Clausilia Rolphii, Brown, lUust. Conch., p. 38, 

 pi. 18, f. 31. 



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 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. 



This species is subject to the following very distinct 

 varieties : 



1. With four plaits, the middle ones less than the others. 



2. With five plaits, the three middle ones less than the 

 others. 



3. With five plaits, the three lower ones less than the 

 others. 



Found first in Britain by Mr. Rolph, in Charlton Wood, 

 Kent ; and Mr. Gray has met with it at Hastings, Sussex. Its 

 habitat is in damp woody situations, among moss, and on the 

 trunks of trees. 



5. Clausilia dubia, pi. IV, f. 41, 42. 



Clausilia dubia, Drapernaud, Hist, des Moll., p. 142, pi. 4, f. 

 10; Alder, Mag. Zool. and Bot., II, p. Ill; Brown, Illust. 

 G 



