OA8TEROP0D0US MOLLUSCA OF BERWICKSHIRE. 2i) 



for that of tho former naturalist by foreign authors, and by some care- 

 less translators in our own country. 



22. Apltsia. Linnaus. 



Animal naked, gastcropodous, hunchbacked, winged on the sides; 

 tho folds partially concealing the shell, which forms a horny pa- 

 telloid shield over the branchice ; tentacula four, ear-shaped ; eyes 

 two, sessile ; sexual orifices on tho right side ; anus placed at tho 

 end of a syphon. — Phytophagous. 



1. A. mustelinay body snail-like, gibbous on the back, of a uniform 

 purplish-red or brown colour, closely speckled with short wavy 

 and inosculating black lines. Length 3-4 inc. Ap. depilans, 

 Penw. Brit. Zool. iv. 78. Flem. Brit. Anim. 290. Ap. muste- 

 lina, H. Davies in Penn. Brit. Zool. iv. 79. tab. 22. Ap. hy- 

 brida, Sowerby, Brit. Misc. 111. tab. 53. 



Ilab. Berwick Bay, near low water mark, not common. 



Head truncate ; mouth inferior, covered by a veil ; anterior tentacula mar- 

 ginal, folded, ear-like; posterior small, tubular at the base, folded 

 above; eyes two, very small, black, encircled by a white halo, placed 

 in front and at the external base of the posterior tentacula ; back gib- 

 bous, encircled with a fin-like expansion of the cloak, the margin 

 undulate, separate before, but continuous behind ; tail depressed, ob- 

 tuse ; foot concave, plane, wavy or even according to the position of 

 the animal. On one side there is a furrow which runs obliquely 

 backwards from the anterior tentaculum, and terminates under tho 

 branchial covers. Shell homy, ovate, narrowest behind, where the 

 apex is oblique and produced into a small mucro, convex dorsally, 

 smooth or very faintly marked with a few lines radiating longitudi- 

 nally, the margin entire, with a membranous border that becomes broad 

 on the wide and rounded front. It resembles pretty closely that of the 

 Aplysia hr<mliana, as figured by Sowerby in his " Genera of Becent 

 and Fossil Shells." The Aplysia often adheres by the posterior part 

 of the foot, which it can contract into a kind of circular sucker ; and 

 it frequently swims, in a reversed position, along the surface of the 

 water. It feeds on sea-weed, particularly on Fuatu palmatvs and n isytis. 

 When alarmed, it pours out, in great abundance, from under the 

 branchial lid, a beautiful purple-coloured liquor, which has a very 

 slight sickening smell, but too faint to occasion any unpleasant sen- 

 sations, nor does it possess any acrid property. This innocuous char- 

 acter of the British species proves it to be distinct from the Aplyria 

 depilans of Linna)us, who, epitomising the history of Bohadtch, says — 

 '' Habitat, in M. mediterraneo ; sanie depilans tactu, fcetidissima ad 

 nauseam usque."* There is a nearer relationship apparently of Ap. 

 tnufiiiina wivh the Ap. fasciata of Poiret, and I have seen a specimen 

 of the former, in which the wings were bordered with a line of bright 

 blue ; but the figure given of Ap. fasciata by Kisso does not represent 



• We may add, that tho figure given of Ap. depilans (nr as he calls it, Ap. Itintrina) by DeUe 

 ChiiOo, leaves no doubt of the species beiog altogether different from tlt« British one.' 



