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

74 MOLLUSCA. [MALLEACEA. GEN0S 6~LI~tA~J3ruguicre. Shell longitudinal, equivalve, in_equilateral; .si?es somewhat thickened, and gaping; umbones d1vergent, the1r mternal facets inclined outwards; hinge provided with two lateral teeth, onc on each side in both valves, which becomc nearly obsoletc in adult shells; arca betwcen thc bcaks to which thc ligament is attaclwd, tripartite; the middle or hingc pit roundcd above, and contains the chicf portion of the ligamcnt, the remaining por- tions are attachcd to thc somcwhat elongatcd linear divisions; muscular imprcssion lateral, suborbicular, from thc inner mar- gin of which the muscular impression of the mantle emanatcs, and travcrsing the outsidc of the valves in a circuitous form, appcars to termínate near thc bcak ; externa) surface covered with a very thin epidermis. l. LIMA SULCATA, pi. XXIII, f. 4, 5. Lima sulcata, First Ed., pi. 31, f. 4, 5; Lcach, MSS., p. 11; Lima suúam·iculm•ia, Flcming, p. 388; Turton, lliv., p. 218; Pecten suúau1·icula1·ia, Montagu, Sup., p. 63. Shell white, pcllucid, oblong-ovatc, equilateral, and equivalve; providcd with small angular auricles; whole surface covered with numerous, longitudinal, divergent striro, with two opaque, cen- tral, rib-like projections emanating from the umboncs, ami ter- minating on the margins, which are crcnatcd ; insicle smooth, glossy, with inclicalions c,f the two externa! ribs. · Length up- wards of three-eighths; brcaclth half its length. First cliscovered on the Devonshire coast, ami has bcen met with in thc Frith of Forth and Zetlaml. A variety of this shell was found in sand, south of J3utc, by StewarL Ker, Esq., in which the Lwo elevated central striro are not so conspicuous, but are imlicated internally; it also differs in ali the strim on the sidcs having intermecliate ones, which are less elevated than the others. 2. LIMA 1 1 1\AGILIS, pi. XXIII, f. G, 7, 7:* Limafragilis, First Ecl., pi. 31, f. 6, 7; Lamarck, VI, p. Hi7; Fleming, p. 388; Forbcs, p. ,10; L-ima úullata, Turton, p. 217, pi. 17, f. 4, 5; Liwi Goodallii, Leach, MSS., p. 11; Pectm fmgilis, l\fontagu, Sup., p. 62; 13rown, Ency. 13rit., p. 418. Shell subovate, very convcx, fragile, white, subpellucid; rnlrns c<¡nal, incquilaternl, one side straight, the other arcuate<l, nearly closed on ali sides, with numcrous, slightly undulating, longitu- dinal stri,c, ami with two or three minute, fine, intermccliate oncs; auriclcs small, oblique ; umbo prominent, small, and straight, thc bcaks distant; insidc smooth, shining, and white; hinge linc a little obliquc. Length upwarcls of three-quarters of an inch; breadth not quite half an inch. Found on the Dernnshirc ami Manx coasts; and at J3ute and Frith of Forth, Scotland. 3. LIMA TENEIIA, pi. XXIII, f. 8, 9. Lima tc11c1·11, First Ed., pi. 31, f. S, 9; Turton, Zoo). Journ., H, p. 3G2, pi. 13, f. 2; Forbcs, p. 41; lb., Mag. Nat. 1-Iist., V, p.1i!H, f. G-1. Shell comprcsscd, incquilatcral, gaping at both sides; anterior sidc somewhat triangular, with thc opening margiued intcrnally, with a strong roundcd rib ; externa! surface furnished with twenty-fivc somcwhat undulatcd, ncarly smooth ribs; margin scrratcd ; hinge linc obliquc. Thi~ spccics is much stronger than thc L .fragilis. First found in the Ilritish Channcl, by Dr. Turton; Forbes found it on the l\fanx coast; and it was detectcd al Lamlash Day, Arran, by James Smith, Ese¡., of Jorclan Hill. 4. LIMA VITRINA, pi. XXIII, f. 10, 10,* 11, 11.* Lima vit1·iiia, First Ecl., pi. 31, f. l O, 11. Shell oblong-ovate, convex, vcry fragile, whitc, and subpcllu- cid; hinge line very oblic¡ue, with a large triangular pit for thc accommodation of the cartilagc socket; umbo small, ancl much turned to onc sidc; whole shell considcrably twisted; the valves gapin<> on both sidcs, with numcrous, slightly undulatcd, notch- ed, clivergent striro, crossed by excccclingly fine, unclulating, concentrie striro, not discoverable without thc aid of a lens, and with many, ncarly obsolete, concentric wrinkles; auricles small, slightly striated transvcrsely; insicle clcar white, ami v~ry glossy. Len<>th ncarly an inch ami a half; breadth about an mch. I found onc valve of this at Ilallantrac, Ayrshirc ; and it \\'ll$ afterwards mct with on thc Argyleshire coast, by Captain Car- michael; and Mr. Stcwart Ker found it on the shores of thc lsland of Ilute. 5. LIM.-\ INFLATA f Lima iizjlafo? Forbcs, l\fag. Nat. Hist., V, p. 593, f. 63; lb., Mal. l\1on., p. 41 ; Lamarck, VI, p. 156? " Shell stroug, inflated with rough longitudinal ribs, crossed by lines ancÍ furrows of growth; gaping on_ ali sides wid_ely. Dimcnsions, length fourtcen-tenths; breadth mnc-tenths; tlnck- ness nine-tenths." Dredged in dcep water off the Manx coast, by Profcssor Forbcs. SECTION III.-Ligament marginal, elongated. FAMILY l.-Jl1ALLEACEA. Shells foliaceous, more or less inequivalve, with a marginal ligamen(, which is partly linear, ami simple, or intcrrupted by crenulations. GENUS 7 ~Av1cULA.-Lamarck. Shcll incquilateral, inequivalve, foliaceous, subquadratc, and oblique; pearlaceous within; hinge rectilinear, ancl procluced on each side into rectilincar appendages, with a small, inclistinct tooth in both valves ; an elongatcd, marginal, ligamentifcrous arca, widened near its centre. l. Av1cuLA ANGLICA, pl. XXIII, f. 3. A ·vicul<t Angl-ica, First Ed., pi. 31, f. 3; Leach, MSS., p. l l. ·Shcl\ very thin, with the hinge linc but slightly bent; cardi- nal lobc short, ami acule above; posterior lobe rather long; whole surfacc concenlrically wrinkled, with imbricated, ncarly equidistan(, scale-like ~pines, running in trans\·crsc series; out- siclc fawn-colourc<l, with intcrruptecl, longitudinal slrcaks of umber-brown, bccoming iriclesccnt towards the base, bcsidcs thc scales, which are aUachcd to thc clcvated striro; al regular inter- vals it is providcd with long, sharp spincs, of a yellowish-hrown colour, which lic closc to the shell. Disco\·cred 011 the Del'onshirc coast, by Dr. Leach. 2. AVICULA ATLANTICA, pi. XL VI, f. G, 7. Aviculci Atlantica, First Ed., pi. 10,"' f. G; Lamarck, VI, P· 148; ¿Jvicula hi1·u11clo, Turton, 13iv., p. 220, pi. 17, f. :l; Flc- ming, p. 405; 11Jytilus hii-wulo, Turton, Conch. D ict., p. 1U1, pi. 1, f. 7.