PHOLAS. 117 



Pholas Candida, Liniuieus. 



Valves not beaked ; surface not divided by a radiating grove ; 

 dorsal plate single. 



Plate IV. figures 1,2. 



PImlas Candida, Linn. Syst. Nat. ed. 12, p. 1 1 1 l(not Spengler). — Penn. Brit.Zol. 

 ed. 1, vol. iv. p. 76, pi. 39, f. 11. — Da Costa, Brit. Conch, 

 p. 246. Pulteney,mHutchin's Hist. Dorset, p. 26. — Donov. Brit. 

 Shells, vol. iv. pi, 132. — Mont. Test. Brit. p. 2.— Dorset 

 Catal. p. 27, pi. 1, f. 12.— Linn. Tr. vol. viii. p. 31.— Turt. 

 Conch. Diction, p. 144, f. 79 ; Dithyr. Brit. p. 10.— Flem. 

 Brit. Anim. p. 457. — M'Gii,. Moll. Aberd. p. 306. —Brit. 

 Marine Conch, p. 31.— Brown, 111. Conch. G. B. p. 115, pi. 

 48, f. 6, 7, 8, 9, 10. — Chemn. Conch. Cabinet, vol. viii. p. 

 358 (not variety), pi. 101, f. 861. — Wood, General Conch, p. 

 79, pi, 14, f. 3, 4. — DiLLW. Recent Shells, vol. i. p. 36. 

 (not variety). — Lam. Anim. s. Vert, ed. 2, vol. vi. p. 44. — 

 Burrows, Elem. Conch, pi. 3, f. 4. — Mawe, Introd. Conch, 

 pi. 3, f. 2.— Wood, Ind. Testae, pi. 2, Phol. f, .3.— Crouch, 

 Introd. Conch, pi. 2, f. 11. — Phimppi, Moll. Sicil. vol. i. p. 3, 

 and vol, ii. p. 4. — Hanl. Recent Shells, p. 5, pi. 2, Phol. f. 3. 

 — Desh. Exp. Sc. Alger, p. 109, pi. IX. D. I. f. 4, 5 (animal). 

 5) papyracea, Spengl, Skrivt. Naturhist. Selskab. vol. ii, part 1, pi. I, f. 4 

 (not of his diagnosis). — List, Hist. Conch, pi. 435, f. 278. 



The outline of this fi-agile shell varies from oblong to 

 elongated oblong ; it is thin, semi-pellucid, dull white, and 

 moderately inflated. Its posterior gape is the more consi- 

 derable, the valves being nearly closed anteriorly. Their 

 surface is simple, covered with fine moderately-distant 

 radiating lines, and closer set concentric sublaminar striae, 

 which, at their intersection, give birth to very short and 

 rather broad prickles or spines, which are chiefly evident at 

 the front of the shell, where the radiating lines are broader 

 and, in most specimens, more distant. The ventral edge is 

 uniformly convex or subarcuated, and slopes upwards ante- 

 riorly : the dorsal edges are convex, but little slopino- 

 behind, more so in front. The sides are very unequal, and 

 both are rounded at their termination ; the posterior end 



