PURPURA. 381 



Buccinuia filosiim, Gmklin, Syst. Nat. p. 3486.— Dillw. Recent Shells, vol. ii. 



p. 614. — Wood, Index Testaceolog. pi. 2.3, f. 63. 

 Pm-pura lapillus. Lam. Anim. s. Vert. (ed. Dash.) vol. x. p. 79. — Fleming, 

 Brit. Anim. p. 341. — Peach, Annals Nat. Hist. vol. xiii. 

 p. 203 (nidus). — Couch, Cornish Fauna, pt. 2, p. 62. — 

 Johnston, Berwick. Club, vol. i. p. 239, with animal. — 

 Macgilliv. Moll. Aberd. p. 166. — Brit. Marine Conch. 

 p. 213.— Brown, Ulust. Conch. G. B. p. 5, pi. 4, f. 4, 5, 6, 7. 

 — Blainv. Faune Franq. Moll. p. 146, pi. 6, f. 3, 4. — 

 KiENER, Coq. Vivant. Purp. pi. 29, 30, 31, figs. 77 (c, d, e, 

 f, k, 1, m, 0, p, q, r, s). — Gould, Invert. Massach. p. 301. — 

 Dekay, New York Fauna, Moll. p. 135, f. 175. — Reeve, 

 Conch. Icon. vol. iii. pi. 10, f. 47. — Middend, Malac. Ros- 

 sica, pt. 2, p. 113. 



„ imbricata. Lam. Anim. s. Vert. (ed. Desh.) vol. x. p. 80. — Dekay, New 

 York Fauna, Moll. p. 136, f. 173. 



„ bito7iaiis. Lam. Anim. s. Vert. (ed. Desh.) vol. x. p. 88 (teste Kiener, 

 Desh. &c.)— Dekay, New York Fauna, Moll. p. 136, f. 174. 



So manifold are the guises in which this shell presents 

 itself, that, were it not that its great abundance and the 

 facility with which it is acquired, have enabled naturalists 

 to perceive the connecting links of the very different look- 

 ing specimens, their specific individuality would assuredly 

 have been denied. These causes, indeed, render the 

 species of much interest to all who strive to ascertain 

 the co-existent conditions by which form, sculpture, and 

 colouring are modified (for it is variable in all these 

 points); and the data obtained by the careful study of 

 a few such species might go far towards the establishment 

 of a sound theory for determining the nice limits of 

 varietal and specific distinction. 



The shell is solid, not lustrous, sometimes of a dusky 

 chocolate brown, but generally white or very pale ochre 

 colour, either uniform in tint or stained in the intervals of 

 the ridges with the darker hue (more rarely the converse) 

 or else banded with yellow, brown, or chestnut ; in the 

 last case a single moderately broad zone usually winds 

 along the upper part of each whorl, a broad medial and 



