Involute.] 



MOLLUSCA. 



19 



nent than the others ; beneath these is a well-defined suture ; these ridges 

 are crossed by numerous very fine, waved, obliquely longitudinal, nearly ob- 

 solete stria;; colour livid, reddish citron, or purplish, streaked with longi- 

 tudinal broad, waved blotches of pinkish red ; these are more regular and 

 distinct on the basal rib of each volution, forming an elegant spiral girdle 

 from the base to the apex ; aperture somewhat compressed and angu- 

 lated; inside highly pearlaceous ; base flatfish, with concentric ridges, 

 crossed by obsolete divergent stria; or lines of growth, generally of a 

 paler colour than the rest of the shell, and usually destitute of spots ; 

 outer lip thin, inner lip a little reflected and thickened, somewhat con- 

 cave behind, with a slight notch at its junction with the outer lip. Length 

 and breadth usually about an inch, but we found it one inch and three- 

 eighths in dimensions, in Dublin Bay and Portmarnock, Ireland. It in- 

 habits the coasts of Cornwall, South Devon, and Tenby, Wales ; Roth- 

 say and Loch Ridan, Scotland. 



Figs. 17 and 18 — A variety presented to us by Dr Leach, who ob- 

 tained it from George Lyons, Esq. of Tenby, Wales, where it is not un- 

 common. 



Figs. 21 and 22 — A beautiful smooth variety, dredged in deep water 

 off Sunderland, by Mr Dixon of Bishopwearmouth. In Lady Jardine's 

 Cabinet. 



Figs. 24 and 29 Another smooth variety, dredged in deep water off 



the county of Down, Ireland. 



9. T. discrepans, pi. XI, f. 20 and 23 First Ed., pi. 45, f. 20 and 



23; Brown, Wernerian Memoirs, II, p. 501, pi. 24, f. 4, 4. 



Shell conic, with seven rounded volutions, well-defined by a hollow, 

 broad, and deep suture, and terminating in a pointed apex ; the whole shell 

 covered with somewhat obsolete spiral ridges ; a deep groove emanates 

 from the centre of the outer lip, and runs spirally to the apex in the mid- 

 dle of the volutions ; aperture subquadraugular ; nacreous within ; cir- 

 cumference at the base nearly an inch, heighth seven-eighths. 



This species has much the aspect of Trochus Zizyphinus, but differs 

 from it in the deep spiral groove ; it is also shorter in proportion to the 

 breadth at the base, and more obtuse at the apex. 



One specimen only of this shell was found at Holywood, in Belfast 

 Lough, by Miss Templeton of Belfast, and was in her Cabinet. 



10. T. papillosus, pi. XI, f. 13, 14 First Ed., pi. 45, f. 13, 14; Da 



Costa, p. 38, pi. 3, f. 3; Donovan, Brit. SI)., pi. 127; Brown, Werne- 

 rian Memoirs, II, p. 519; lb., Ency. Brit., VI, p. 452; Fleming, Brit. 

 An., p. 323; Trochus tenuis, Montagu, p. 275, pi. 10, f. 3. 



Shell conic, thin, fragile ; with eight slightly inflated volutions, terminat- 

 ing in a fine pointed apex, and separated by a very slender suture; whole 

 shell ornamented with numerous regular series of papillose, spiral zones, 

 each separated by a groove, in which is placed a raised, central, spiral 

 line, crossed by very close and minute longitudinal, nearly obsolete stria;; 

 the volutions are defined by a larger and more elevated zone of papilla; 

 at their base, which on the body forms a distinct keel; base somewhat 

 tumid, with numerous spiral grooves and ridges, on which latter the pa- 

 pilla; are less distinct than above ; the whole are crossed by numerous, 

 more obvious, divergent striae; aperture wide, quadrangular, grooved, and 

 nacred within; outer lip very thin; columella thick, with an obsolete 

 plication near its base, where it is slightly reflected, with a concavity be- 

 hind; colour citron, or pinkish-brown, the zones on the base studded 

 with rather regular, oblong, or arrow-shaped, reddish-brown spots. 

 Length an inch and a quarter; breadth rather less. Found at Pool and 

 Weymouth, Dorsetshire; Cornwall; north coast of Devonshire, from 

 whence we obtained the splendid specimens which we have figured, mea- 

 suring an inch and a half in length and breadth, found also in Dublin 

 Bay, and in deep water off Bray, Ireland. 



11. T. striatum, pi. XI, f. 25, 26 First Ed., pi. 45, f. 25, 26 ; T. ery- 



Ihrolcucos, Brown, Ency. Brit., VI, p. 452; Turton's Linne, V, p. 463; 

 Lamarck, VII, p. 30; Trochus striatus, Montagu, p. 278; Fleming, Brit. 

 An., p. 323; Trochus conicus, Donovan, Brit. Sh., pi. 155, f. 1 ; Turton, 

 Brit. Fau., p. 177; Trochus parvus, Da Costa, p. 41. 



Shell conic, strong, with six flat volutions, hardly defined by the su- 

 ture, and tapering to a fine point, with eight or nine strong spiral strix' 

 on each volution, intersected by very minute longitudinal stria?, most con- 

 spicuous on the body and base, which is flattened and somewhat con- 

 cave with circular ridges ; cinereous, or reddish flesh-coloured, with large 

 longitudinal, interrupted, zigzag dull crimson, or purplish-brown clouds j 

 broad in some specimens and narrow in others ; aperture obliquely quad- 

 rangular, pearlaceous within, except at the margin of the outer lip, which 



is rather strong for its size ; columella thick, a little reflected above and 

 narrower beneath, with a slight concavity behind. Length three-eighths 

 of an inch; breadth nearly the same. 



Found in sand at Falmouth, Cornwall ; Salcomb Bay, Devonshire, and 

 Pool, Dorsetshire. It is a rare British shell. 



12. T. exiguus, pi. XI, f. 27, 28 — First Ed., pi. 45, f. 27, 28; Mon. 

 tagu, p. 277; Turton, Brit. Fauna, p. 177; Trochus conulus, Da Costa, 

 p. 40, pi. 2, f. 4, 4; Brown, Ency. Brit., VI, p. 452; Donovan, Brit. Sh., 

 I, pi. 8, f. 2; Lamarck, VII, p. 24; Trochus cxasperatus, Pennant, Brit. 

 Zool., IV, p. 126, No. 105. 



Shell conic, strong, with six flat produced volutions, separated by a 

 strong spiral belt at the base of each, and terminating in a fine pointed 

 apex, each volution ornamented with four or five well-defined spiral cre- 

 nated ridges, which being cut diagonally with strong stria;, give them the 

 appearance of twisted cord, with deep intervening grooves, crossed bv 

 strong oblique strix; base slightly rounded, with strong circular ridges, 

 striated in the same direction, and crossed by divergent, nearly obsolete 

 stria;; aperture obliquely quadrangular, whitish, pearly within; outer lip 

 strong; columella thickened and pearlaceous, with an obsolete tooth-like 

 process near its base ; colour various, cinereous, brown, dull purplish- 

 brown, sometimes reddish, and spotted with white ; apex almost constant- 

 ly of a deep crimson, which frequently extends to the second volution ; 

 sometimes the spiral zone at the base of the volutions is ornamented with 

 square crimson spots. Length rarely three-eighths of an inch; breadth a 

 quarter of an inch. 



This and the preceding species have not unfiequently been confounded, 

 but may at once be distinguished from the T. striatus by its being much 

 more produced, in the spiral ridges being crenated, the base being rounded, 

 the tip of the spire almost invariably crimson, and the inside of the aper- 

 ture very slightly nacred. 



Found on the Sussex and Devonshire coasts, and at Trcryn Cove, near 

 the Land's End, Cornwall. Montagu found it on the shore between Wey- 

 mouth and Portland. It is a rare and very local British species. 



13. T. craitus, pi. XI, f. 6,7 — First Ed., pi. 45, f. 6, 7; Montagu, p. 281 ; 

 Brown, Ency. Brit., VI, p. 452; lb., Wernerian Memoirs, II, p. 519; 

 Turton, Brit. Fan., p. 177; Fleming, Brit. An., p. 322; Turbo lineatus, 

 Da Costa, p. 100, pi. 6, f. 7 ; Donovan, Brit. Sh., II, pi. 71. 



Shell subconic, very thick and strong, with five rounded volutions, 

 separated by a veil-defined suture, apex pointed, but not sharp; base 

 somewhat produced and rounded at its edge; aperture 1 pearlaceous within ; 

 suborbicular, somewhat angulated at the junction of the outer lip and 

 pillar, and rounded next the outside; outer lip acute, its inner margin 

 dark purplish brown j columella smooth, white, or nacred, with a blunt 

 tooth-like process below its centre; and a slight groove behind the co- 

 lumella, and in others it is slightly subumbilicate ; outside coarse and 

 wrinkled; colour cinereous, or light fawn, covered witli fine, close-set, 

 zigzag lines of purplish-brown, and sometimes of a blackish purple; a 

 white semilunar patch covers nearly half of the base. Length an inch, 

 breadth somewhat less. 



This species is subject to some variation in shape ; some are more 

 conic, and the volutions more rounded and tumid than others. 



Found on the coasts of Cornwall, Devonshire, Hampshire, Caernar- 

 vonshire, Wales ; Dublin Bay, Killough, and plentiful on the rocks at 

 Limerick, Ireland. 



Family II Scalarides. 



Shell devoid of plaits or folds on the columella; margins of the 

 aperture united in a circular form. 



Genus 21 Delphionoidea Brown. 



Spire depressed, surface smooth, divested of spinous processes; 

 aperture orbicular, or nearly so, and not enveloping the body vo- 

 lution. 



Subdivision 1 — Volutions Dc.i'frtit. 



1. D. Unispirala, pi. VIII, f. 32, 33.— First Ed., pi. 51, f. 32, 33. 



Helix unispiridts ; Montagu, p. 443 ; Maton and Racket, Linn. Trans., 

 VIII, p. 201 ; Walker, Minute Shells, f. 27. 



Shell glossy white and opaque, with one volution, umbilical e on both 

 sides; aperture orbicular. Diameter scarcely a line. 



Found at Sandwich, and is very rare. 



