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Show 438 MOLLUSCA. closed by two or four valves. This tube is formed of various pieces, which appear to be detached, and separated in proportion as the growth of the animal requires it. The branchice, mouth, articulated tentacula, and the anal tube~ differ but little from those of the Anatifce. In BALANUS Properly so called, the tubular portion is a truncated cone formed of six projecting pieces, separated by as many depressed ones, three of which are narrower than the others. Their base is usually formed of a calcareous lamina, and fixed to various bodies. The four valves of their operculum close the orifice exactly. The rocks, shells, &c., on the coast of Europe, are, in a man· ner, covered with a species of Balanus, the Lepas balanus, L., Chemn., VIII, xcvii, 826, 1(1). Naturalists have separated from it The AoASTlE, Leach, whose base is irregular, convex towards the exterior, and which does not become fixed; most of them are found in sponge(2); The CoNilE1 Blainv., the tube of which has but four salient pieces(3). The AsEMlE, Ranzani, where the tube has no decidedly salient pieces( 4); The PYRGOMlE, Savigny, whose tubular position, forming a strongly depressed cone, has but a very small orifice, almost like the shell of a Fissurella( 5); The OcTHOSilE, Ranzani, which have but three salient pieces in the tube and only two valves to the operculum( 6); The CREUSilE, Leach, with four salient pieces, and two valves to the operculum(7). (1) Add, Lepasbalanoi'des, Chemn., Vlll, xcvii, 821-825;-L. tintinnabulum, lb ., 828-831;-L. minor, lb., 827;-L. porosa, Id., xcviii, 836;-L. verruca, lb., 840, 841;-L. angusta, lb., 835;-L. elongata, lb., 838;-L. patellaris, lb., 839;L. spinosa, Ib., 840;-L. violacea, 1<.1., xcix, 842;-L. tulipa, Ascan. Icon., X;-L. cylindrica, Gronov., Zooph., XIX, 3, 4;-L. cariosa, Pall., Nov. Act. Petrop., JJ, vi, 24, A, ll. (2) .!J.casta Montagui, Leach, Edinb. Encyc., copied Blainv., Malac., lxxxv, 3; -Lepas spongites, Poli, I, vi, 5. (3) Gonia radiata, Blainv ., Mal::tc., lxxxv, 5. (4) Lepas porosus, Gm., Chcmn., VIII, 'xcviii, 836, 837, Encyc. Method., pl. 165, £ 9, 10. (5) Pyrgoma cancellata, Leach, loc. cit., copied Blainv., Malac., 1xxxv,5. (6) Lepas Strcemii, Miill., ZooL Dan., Ill, xciv, 1-4. (7) Creusia spinulosa, Leach, loc. cit., copied Blaim·., Malac., bcxxv, 6. CIRRHOPODA. 439 M. Delamarck, under the name of CoRONUL.JE, separates the ver wide species, where the parietes of the cone are occupied by cell~ so large that they resemble chambers( 1 ); and under that of TuBIOINELLlE, those in which the tubular portion is elevated narrower near the hase, and divided into annuli, which mark it; growth(2). There are some species of these last two subgenera, which affix themselves to the skin of the Balcence, and even penetrate into their blubber. To the preceding subgenera must be added the DrADEMA, Ranz. Where the tubular portion is almost spherical, and which has but two small valves almost hidden in the membrane which closes the operculum. The opercular valves would not effectually close the orifice without the membrane which unites them. They also live on the Balcence, and Otiones are frequently observed attached to their surface(3). (1) Lepas balamaris, L., Chemn., VIII, xcix, 845, 846;-L. testudinarius, lb., 847, 848, which attaches itself to the shell of Tortoises. (2) The Tubicinella, Lam., Ann. du Mus., I, xxx, 1, 2. (3) Lepas diadema, Chemn., Vill, xcix, 843, 844. |