Illustrations of the recent conchology of Great Britain and Ireland, with the description and localities of all the species, marine, land and fresh water

CONCIIACEA.] MOLLUSCA. 93 two_ latc1:al, remole, musc'.1lar impressions; pallial impression e:1t1re; ligan.icnt externa!, mscrlcd into a cleep marginal, poste- nor, dorsal smus. l. Cniu~A VULGARis, pi. XXXVII, f. l,and pi. XXXVIII, f. 11. C!Jprina Islrmclica, First Ed., pi. 18, f. 1, ancl pi. 19, f. 11 ; Lamar~k, Y, p. 557; Fleming, p. 4,13; Forbes, p. 47; Venus Islancl1ca, Donovan, III, pi. ii; llfontagu, p. 114; Turton, lliL, p. 135; Venus mercinciria, Pennant, IV, p, 9·1, pi. 53, f. 47. Shell strong, thick, convex, suborbicular; umbones large, pointecl, approximate, placed near the anterior sicle, and much inílectecl, destitute of a lunule beneath them; outer surfacc with numcrous, rather closc-set, conccntric, somcwhat irregular striro, and covcrcd by a strong, horny, blackish-brown, glossy epidermis, which assumes a wri11klecl, suhlamellated character towanls the base of the valves; insiclc smooth, white, but not glossy; pallial impression destitute of a sinus; margin plain, ancl acule. It has been found upon comparison, that this shell is not identical with C. lslcmdica. This spccies is not uncommon in deep water, on most of the British ami lrish coasts. The orclinary size of thc shcll is that on pi. XXXVII, f . 1; and the gigantic spccimen from which I took f. 11, pi. XXXVIII, was dreclged in thc Irish Channel, and is in thc cabinet of William Nícol, Esq., of Eclinhurgh. In the young condition, this shcll is covered with a shining, pale yellowish chestnut-coloured epidermis. GENUS 1,t-LAS,EA,-Leach. Shcll equivah·e, incquilateral, somcwhat inllatcd; hinge not quite central; with approximatc, small cardinal, and a remole, lateral, conspicu·ous tooth in one valve, and a concavc, remole, strong, lateral tooth in tlrn other; margin plain; ligament in- terna!. l. LAS,EA nU0RA, pi. XXXVI, f. 17, 18. LasaJa 1·1tbm, First Ed., pi. 20, f. 17, 18; Leach, MSS., p. 7; Brown, Conch. Text Book, p. 128, pi. 16, f. 16; Cai·dimn nibntm, Montagu, p. 83, pi. 27, f. 4; Maton ancl Ilackctt, p. 66; l(ellin 1·11brn, Turton, Biv., p. 57; Fleming, p. 430; Forbes, p. 49. Shell convex, inequilateral, somewhat broadcr than long, smooth, glossy, pellucicl, of a purple-red colour; umbones producccl, very slightly inllcctecl; hinge with nearly obsolete, car<linal tecth, the lateral ones clistinct; insidc glossy, red; mar- gin plain. Diameter not an eighth of an inch. Inhabits the crevices of rocks on most of the British ancl Irish coasls. Suu-D1v1s10N.-FLU\'JATtLE. Shells covered with a spurious epidermis, ancl the hingc pro- vided with lateral teclh. 2A GENUS 15.-CYCLAs,-Lamarck. Shcll thin, equivalve, subcquilateral, rnntricosc, transversc, or scmiorbicular; closed ali round; bcaks moslly lumid; car- dinal tecth l"ery sma!I, sometimes hardly perceptible; with one plicated or lobccl tooth in the lcft rnll"e, ancl two divcrgcnt in the other; lateral teeth trans,·crscly clongatecl, acule, com- pressecl, or lamcllifonn, double in the lcft Yal\"C; clothcd with a thin, horny epidermis; two lateral, ovale, nrnscular imprcs - sions; pallial impression cntire, destitute of a sinus; ligamcnt externa(. l. CYCLAS RIVICOI.A, pi. XXXIX, f. 16, 17, 18. Cgclas rivicola, First Ed., pi. 17, f. 12 ; Lamarck, V, p. 558 ; C!Jclas C01'11ea, Pfciffer, Land un \Vas. Se., p. 121, pi. 5, f. 3, ,1, 5; Turton, Brit. Bir., p. 248, pi. 11, f. 13; lb., Man., p. 12, f. 1 ; Fleming, Brit. An., p. ,153; Al<ler, Mag. Zoul. all(I Bot., II, p. 118; C!Jclas cornea, Drapcrnaud, Hist. des Mol!., p. 128, pi. 12, f. 1, 2, 3; Tellina cornea, \Vood, pi. 46, f. 3; Canlium col'llettm, llíontagu, p. 86. Shell thin, pcllucid, convex, ovate; covcred by a horny- green epidermis, frequently markcd with palcr lransYcrsc zoncs; fumished with strong, closc, regular, concentric strim; umhones obtuse, central, ami slightly turnccl to onc side; hinge wi th a very small cardinal tooth in the lefl va!Yc, which fits into the space between two small, hut rather produced teeth in the oppositc valve; both valvcs providecl with pro- minent, lateral, laminatecl tecth on each side, those of thc right valve hardly rising above the margins, but in thc lcft valve projecting considerably beyoncl them; inside smooth, bluish-whitc, dull in the concave disk, but glossy towards the margin; an indistinct, pretty largc, muscular imprcssion nenr tite anterior margins, and a narrower, obscure ouc in the pos- terior sides. This is the largest spccies of the genus, somctimes mea- suring five-eighths of an inch in lcngth, and seven-eighths in brcadth. Found plentifully in the Thamcs al l3al tersea, ami also ncar Red House, all(I in the 11cighbourhood of Oxforrl; of a largc size in the Trcnt, near Ilurlon; ancl in many slow rivers in Englancl. 2. CYCLAS CORNEA, pi. XXXIX, f. 19. Cyclas conzea, First Ed., pi. 17, f. 15; Pfcilfer, p. 120, pi. 5, f. 1, 2; Turton, llrit. Biv., p. 248, pi. 11, f. 14; lb., Man., p. 13, f. 2; Flcming, Brit. An., p. 452; Forbcs, p. 49; Thomp- son, Ann. ancl llfag. Nat. Hist., VI, p. 52; Alder, Mag. Zoo(. and Uot., II, p. 118; C!Jclas rivalis, Drapernaucl, Bist. des Mol!., II, p. 202, No. 387; Tellina cornea, Gmelin's Linné, I, p. 1120, No. 72. Shell subglobular, ventricosc, thin, semitransparcnt; with concentric, nearly obsolete striro; umbones oblusc; epidermis grecnish horn-colour, with darker zones, aucl borclered with a broad, ycllowish band; inside dull bluish-whitc. Lcngth three and a half eighths of an inch; breaclth half an inch. A vcry clistinct variety, consiclcrably Iess than the ordinary size, with the teeth larger in proportion, and of a lcmon-ycllow colour, was founcl by Mr. Glovcr, in the Leven, not far from Ambleside.