GASTEROPODOTTS MOLLUSCA OF BER-WICKSHIRE. 239 



the outer fold of the pillar. Length -j^j-ths. Flem. Brit. Anim. 

 340. Buccinum macvila, Dillw. Rec. Sh. 638. 



Kah. Berwick Bay, at and within low water mark, frequent. 



" The shell has frequently a red band on the centre of the body-whorl ; and a 

 beautiful variety is sometimes found entirely red." — iU>- J. AlcLer. 



Animal straw-coloured, speckled with black ; teutacula setaceous, bulged at the 

 base, the eyes placed half-way up on their outer side ; syphon long brown 

 speckled and black near the base, either straight and projected, or retro- 

 verted and laid on the back of the shell when in motion ; foot and collar 

 plain : mouth with a long proboscis, thicker towards the apex, and, aa 

 usual, furnished with filiform striate tongue. The animal is active, and 

 tolerably quick in progression. 



5. Purpura. Lamarck. 



Shell oval, thick, ribless ; aperture dilated, ovate, with a short -wide 

 canal ; pillar flattened ; outer lip without a varix : operculum horny. 



1 . P. Lapillus^ shell ovate-acute, white, obsoletely ridged in a spiral 

 direction ; whorls six, those of the spire small, the suture obscure ; 

 aperture oval, tinged with purple, the outer lip thick, toothed 

 within ; pillar plain, with a thick fold at the base. Length 1 births, 

 breadth vo-ths. Lam. Anim, s. Vert. vii. 244. Flem. Brit. Anim. 

 34L Buccinum lapillus, Linn. Billw. Kec. Sh. 613. Purple 

 Fish, Cole in Phil. Trans, xv. ann. 1685, p. 1278, tab. 3. fig. 3-8. 



Kdb. Berwick Bay, between tide marks, abundant. 



Immature shells are often marked with bands of brown or yellow, and the 

 spiral ridges or ribs are roughened with scales, a variety which constitutes 

 the P. imbricata of Lamarck. 



Anim;il; tentacula 2, dorsal, tapered, flattish, dilated below the eyes which are 

 inserted in an incisure near their middle nnd on the outside : mouth with 

 a short proboscis : margin of the cloak plain, marked with a brown band • 

 foot short, plain, oval, the brown liorny operculum placed on its back • 

 branchico in two very unequal pectinated processes adnate to the syphonal 

 side of the respiratory cavity ; penis flat, curved, retroflexed, obtuse with 

 a terminal mucro. 



The nidus of this animal is very different from that of Fusus or Buccinum • 

 and we may add from the typical Purpura3, from which our shell has been 

 separated by Mr Swainson, and placed in his now genus Pohjtropa. It ia 

 descriljed by Ellis (Corall, p. 87. tab. 32. fig. c. c.) as an " Alcyonium sea 

 cyathus marinus," and is in the form of a wine-glass or vase, adherino- by 

 a broad base, and hanging in general from the roof of shelvincr rocks in 

 considerable chisters. " When they are first taken out of the sea, they are 

 of a bright semi-transparent yellow colour, of a horny tough natui'e con- 

 taining a viscid substance, with many orange -coloured seed, or egg-like 

 particles, in the upper part of each cup," and in which the little shells 

 completely formed, are soon to be detected with the magnifier. Each 

 nidus is distinct or separate, with a short narrow neck, and the upper part 

 oval, containing the ova or young covered by a convex lid, which at length 

 opens to admit of their escajie. 



On the back of the snail there may be observed a pale-coloured vessel winding 

 obliquely backwards, and filled with a liquor of the colour and consistence 

 of cream. This liquor affords an indelible dye of a fine purjjle colour 

 analogous or perhaps identical vrith the Tyrian purple of antiquity. The 



