()0 COLIMACEA. 



Sttb- Genus 2. — Helicigona. — Ferussac. 



Shell orbicular^ depressed, equally convex both above and 

 below; umbilicate ; provided with a carina on the centre of the 

 body ; aperture transverse ; lips united all round. 



7. Helix lapicida, pi. VII, f. 1, 2, 3. 



Helix lapicida, Linne, Syst. Nat., p. 1241 ; Gmelin, Linn. 

 Syst., p. 3613, No. 2; Muller, Verm., II, p. 40, No. 240; 

 Donovan, Brit. Sh., II, pi. 29, f. 2 ; Pennant, Brit. Zool., IV, 

 p. 132, pi. 83, f. 121 ; Drapernaud, p. Ill, pi. 7, f. 35, 36, 37; 

 Brard, p. 53, pi. 2, f. 14, 15; Fleming, Edin. Ency., VII, p. 

 80 ; Brown, Ency. Brit., 6th Ed., VI, p. 457 ; Rossmassler, I, 

 p. 63, pi. 1, f. 1 1 ; Caracolla lapicida, Lamarck, An. San. Vert., 

 VI, pt. 2nd, p. 99 ; Fleming, Brit. An., p. 258 ; Alder, Mag. 

 Zool. and Bot., II, p. 109; Turton, Man., p. 66, pi. 5, f. 51; 

 Helicigona lapicida, Ferussac, Prod., p. 1 50, pi. &Q,* f. 6 ; 

 Chilotrema lapicida, Leach, Moll., p. 106; Helix acuta, Lister, 

 Conch., pi. 3, f. 4 ; Da Costa, p. 55, pi. 4, f. 9 j Helix lapicida, 

 Brown, lUust. Conch., p. 45, pi. 17, f. 9, 10, 11 ; lb., First Ed., 

 pi. 40, f. 9, 10, 11. 



Shell depressed, subdiscoidal, equally convex above and 

 below ; body large ; spire short, consisting of five much flat- 

 tened, slightly ventricose volutions, terminating in an obtuse 

 apex ; body with a central, sharp-edged carina, which emanates 

 from the margin of the outer lip, and investing the body, 

 continues spirally at the base of the superior volutions, and 

 defines them by a fine thread-Uke ridge; whole shell with 

 strong, wrinkled, longitudinal striae, its entire surface presenting 

 a shagreen-like aspect ; base provided with a large and deep 

 umbihcus, exhibiting the spiral convolutions ; aperture broad, 

 subovate, with a sharp margin ; outer lip white, reflexed, and 

 continuous with the pillar lip, which is a Uttle spread on the 

 base of the body, and both lips disunited from the body. 



This species is extremely local, and appears not to extend 

 nmch further north than the centre of England. It has never 

 been found in Ireland, according to the account of Mr. Thomp- 

 son. Its favourite habitat is hmestone rocks and chalky soil. 



