20 



MOLLUSCA. 



[Trachelipoda. 



2. D. deprcssa, pi. VIII, f. 35, 30. First Ed., pi. 51, f. 35, 3G. 



Helix deprcssa; Montagu, p. 439, pi. 15, f. 5; Turbo depressut ; Tur- 

 ton, Brit. Faun., p. 185; Skenea depressa; Fleming, Brit. An., 313. 



Shell subdepressed, subpellucid, with three or four volutions; spire 

 well defined by the suture, but scarcely elevated above the body, and 

 Blightly wrinkled across; apex distinct, but not produced; body cylindri- 

 cal, base rounded, with a large umbilicus, in which the superior volutions 

 are seen ; aperture obicular, the lips continuous, even all round, and not 

 clasping tin- body, but spreading slightly upon it ; colour of a light brown. 

 Diameter hardly a line. 



Found at Whitsand Bay and Falmouth, Cornwall; Burrow Island, 

 Devonshire; and at Dunbar, Frith of Forth. 



.'!. D. scrpu/onlca, pi. VIII, f. 40, 41 ; First Ed., pi. 51, f. 40, 41. 



Helix serpuloides; Montagu. Sup., p. 147, pi. 21, f. 3; Skenea serpu- 

 loidci; Fleming, Brit. An., p. 313. 



Shell compressed, glossy, white, with three smooth volutions ; spire 

 hut little elevated above the body, and terminating in a small but not 

 pointed apex ; aperture orbicular, slightly adhering to the body, and 

 turning considerably downwards, forming a large and deep umbilicus, in 

 which the superior volutions are distinctly visible. Diameter not a line. 



Found on the Devonshire coast, extremely rare. 



This bears some resemblance to the D. depressa, but differs in the 

 slight connection of the volutions, and their more cylindrical form beneath ; 

 it differs also in colour. 



Subdivision II. — Volutions Sinistral. 



4. D. resupinata, pi. VIII, f. 45 and 47 ; First Ed , pi. 51, f. 45 and 47. 



Helix rcsupinala ; Montagu, p. 444; Walker, Minute Shells, f 24. 



Shell with three reversed volutions, and terminating in an obtuse apex ; 

 aperture large, oval, and not spreading on the body. 



Genus 22 Spira Brown. 



Shell smooth, nearly globular, or semiovate ; spire small in pro- 

 portion to the size, of the body, and depressed ; aperture enveloping 

 the body. 



1. C. globosa, pi. VIII, f. 34 and 37; First Ed., pi. 51, f. 34 and 37; 

 Delphinoidca globosa. 



Helix globosa; Montagu, p. 444; Maton and Racket, Linn. Trans., 

 VIII, p. 203; Walker, Minute Shells, f. 25 ; Turton, Brit. Faun., p. 190. 



Shell smooth, white, opaque, glossy, and round, with two volutions, 

 the superior one slightly elevated above the body ; aperture suborbicular, 

 and clasping the body ; outer lip thin, entire. Diameter not a line. 



Found on the coast of Sandwich. 



2. C. nitidissima, pi. VIII, f. 42 and 44 First Ed., pi. 51, f. 42 and 



44 ; Delphinoidca nitidissima. 



Helcx nitidissima; Montagu, p. 447; Maton and Racket, Linn- Trans., 

 VIII, p. 205; Adam's Linn. Tr., V, p. G, pi. 1, f. 22, 23, 24. 



Shell neatly globular . extremely glossy and' horn coloured; pellucid, 

 with two volutions, finely striate transversely ; base rounded with a small, 

 round umbilicus ; aperture semilunar, enveloping the body ; outer lip 

 plain. Diameter not a line. 



Found on the coast of Pembrokeshire. 



3. C. coarctata, pi. VIII, f. 43 and 52 First Ed., pi. 51, f. 43 and 



52 ; Delphinoidca coarctata. 



Helix coarctata; Montagu, p. 447; Maton and Racket, Linn. Trans., 

 VIII, p. 205; Walker, Minute Shells, f. 30. 



Shell nearly globose, white, and pellucid ; with two volutions ; body 

 very large, superior volution extremely small ; aperture subrotund, em- 

 bracing the body contracted at the base ol the columella; outer lip thin 

 and plain ; an extremely small umbilicus. Diameter not a line. 



Found at Sandwich, very rare. 



4. C. reticulata, pi. VIII, f. 38, 39 — First Ed., pi. 51, f. 33, 39; 

 Delphinoidca reticulata. 



Helix reticulata; Montagu, p. 444; Maton and Racket, Linn. Trans., 

 VIII, p. 203; Adams, Micr., pi. 14, f. 12; Walker, Min. Sh., f. 20. 



Shell semiovate, subglobular, white, and pellucid, with two volutions, 

 spirally and transversely striate ; aperture nearly orbicular, clasping the 

 body; margin of the outer lip plain, and divested of stria; ; base with a 

 subumbilicus. Diameter not quite a line. 



Found at Reculver; extremely rate. 



5. C. bicolor, pi. VIII, f. 50, 51 First Ed., pi. 51,'/. 50, 51 ; Del- 



vhinoidca bicolor. 



Helix bicolor; Montagu, p. 447 ; Maton and Racket, Linn. Trans., 

 VIII, p. 205; Adams, Linn. Trans., V, p. 4. 



Shell with two smooth, pellucid, but not glossy volutions, of a yellow- 

 ish born colour ; base provided with a very small umbilicus. 



This species diflcrs from the C. nitidissima, in being perfectly smooth, 

 not glossy, and in the inside of the shell being white. 



0. C. tubulatu, pi. VIII, f. 40 First Ed., pi. 51, f. 40; Dclphinoidea 



tubulata. 



Helix tubulata; Montagu, p. 440; Maton and Racket, Linn. Trans., 

 VIII, p. 204; Adams, Linn. Trans., Ill, p. 07. 



Shell globular, with three longitudinally striate volutions, and a marginal 

 tube at the base in place of an umbilicus, extending beyond the base of 

 the shell. 



7. C. variegataf 



Helix vaiicgata; Montagu, p. 440; Adams, Linn. Trans., Ill, p. 07. 



Shell consisting of four subpellucid, smooth volutions, with red linea- 

 tions; the body ventricose, and imperforate at the base; margin of the 

 aperture very much spread. 



Genus 23 — Planaria. — Brown. 

 Shell discoidal ; spire depressed ; the volutions apparent on both 

 sides, and encompassed by the body, or outer one ; aperture trans- 

 verse and semilunar, and not clasping the body. 



1. P.pellucida, pi. VIII, f. 53-54-55 First Ed., pi. 51, f. 53-54-55. 



Shell depressed, very thin, pellucid, white, and extremely glossy, con- 

 sisting of four rounded volutions, slightly wrinkled across, visible on both 

 sides of the disk; the one next the body above nearly parallel with it, the 

 inner ones descending into a deep umbilicus; the centre volutions encom- 

 passed by the body; aperture semilunar, transverse, and oblique; outer 

 lip thin, pillar lip adhering to and slightly reflected on the columella ; base 

 rounded. Diameter a quarter of an inch ; thickness not an eighth. 



Found on the coast at Dunbar, by General Bingham, and in his cabinet; 

 and we have lately met with it in the same locality. 



2. P. alba, pi. VIII, f. 48-49 First Ed., pi. 51, f. 48-49. 



Shell depressed, with four milk-white rounded volutions, visible on both 

 sides, encompassed by the body ; the second ones very slightly elevated 

 above the sides of the body, the central ones sinking into a deep umbili- 

 cus ; base rounded, the volutions retiring towards the middle, and winding 

 to a small central umbilicus; the whole crossed by very minute lines of 

 growth, or obsolete strise; aperture oblique, large, suborbicular, and white 

 within; outer lip thin, and plain; pillar lip adhering to the columella. 

 Diameter three-eighths of an inch, and about half that thickness. 



Found on the beach betwixt St Abb's Head and Dunbar by General 

 Bingham, and in his cabinet ; and we have lately found it close to Dun- 

 bar. 



This species has much the aspect of l'lanorbis corneas, but differs from 

 it in the volutions of the apical side, being the reverse of that shell in 

 the inside being parallel with the sides of the body, and in the others being 

 thicker and less sunk than the under side of the P. corneiu, in its young 

 state. 



Genus 24 Scalaria Lamarck. 



Shell turreted ; volutions gibbous, very distinct, sometimes quite 

 separated, with a spiral void in place of a suture, with close or dis- 

 tant, longitudinal, elevated, acute, oblique ribs, sometimes so thick- 

 ened as to present a varicose appearance, but in a few instances so 

 depressed that they hardly appear above the surface; aperture for 

 the most part orbicular, or generally a little longer than broad, with 

 its margin united all round, thickened, and reflected, particularly so 

 in such species as the volutions are apart from each other; lower 

 part of the columella indistinctly canaliculate ; aperture provided 

 With a thin, horny, spiral operculum. 



1. S. communis, pi. VIII, f. 13 First Ed., pi. 51, f. 13; Scalaria com- 

 munis; Lamarck, VI, pi. 2, -p. 228; Scalaria ctal/trus ; Fleming, Brit. An., 

 p. 311 ; Turbo clathrus ; Pennant, Brit. Zool., IV, p. 129, pi. 82, f. 3 ; 

 Maton and Racket, Linn. Trans., VIII, p. 170; Montagu, Sup. p. 120; 

 T. clathratulus ; Donovan, Brit. Sh., pi. 28, upper figs. ; Turbo scalaris ; 

 Montagu, p. 290. 



