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

Co:-;cuAcE.1.J MOLLUSCA. 91 ¡, \'1,:-;us CASINA, pl. XXXVI, f. 15."' Cl1111si1rn C11si11a, First Ecl., pi. 20, f. 15 ;'" Venus Casi11a, T .imu\ p. 1130; Pcnnant, pi. 5-1, f. 48 A; i\faton ami Hackcll, p, ¡!), pi. 2, f. I; Tmton, Iliv., p. 1·11, pi.!), f. l; Montagu, Sup., p. ·li; Flcming, p. •l·IG; Forbes, p. 52; Venus laclea, Donol'an, pi. l •I!). Shcll suborhicular, Ycry thick, hca"y, ami rathcr inllatccl; proYidcd \\'ilh numcrous, transvcrsc, much elevated, laminar, conccntric riclgcs, subcrcnulatccl 011 the posterior si<le; the intenening furrows with ne:ll'ly obsolete, transYerse striro; um- honcs not promincul, acutc, and tumcd to thc anterior sidc, hencath \\'hich is a cordifonn, short, <lceply dcfine<l lunule, co,·crccl with longitudinal, fine stri::c; colour ycllowish-white, or pale rusty-brown; insidc dull white; margin vcry broad, finely crenatcd, grcatly thickcned 011 the eclgc, and covercd with a tlark blackish-brow11 colourccl, laminatccl epidermis. Fouml in the Uritish Channcl, off thc Jsle of Man; many parts on thc coasts of Irelanc.l; ami al Caithncss, Scotlan<l. 8. YE1'US llEFLEXA, pi. XXXVII, f. 12, 13. Clausi1w ?·cjlc.1:a, First Ecl., pi. 19, f. I2, 13 ; Penus ?'ejlc.i-a, Laskcy, Wcrncrian Mcm., I, p. 38,1, pi. 8, f. 1; Montagu, Sup., p. -10 ami 168; Tmton, Biv., p. 142, pi. 10, f. 1, 2; Flcming, p. 4-IG. Shcll suborbicular, rathcr strong, subcomprcsscd ; umbones small, consiclcrably inílcctcd; bcneath thcm an oblong, cordi- form lunulc, elevatcd in the centre, ami of a rcddish-brown colour; posterior or cart.ilage side broad; whole surfacc covered with numcrous, iucquiclistant, transverso, thin, rcllccte<l, lamina! ridges, which are coverecl with cxtremcly fine, <lccussatcd stri::c; on the anterior si<lc thcy are vcry sharp, more clcvated ancl undulatccl, and turn in a contrary dircction to othcr parts, sometimos with a small intervcning one, irregularly disposccl; the fu1Tows are beset with numerous, ncarly obsoletc, longitu- dinal stri::c, which can only be secn by thc aicl of a lcns; colour pale ycllowish-brown or cre:un-white, with two or t.hrcc intcr- rupted, longitudinal, rcclclish-brown radii, consisting of sagittate spots, which point towarcls the umboncs; insiclc whitc; hingc with thrce strong tceth in both valvcs, thc micldlc one slightly bificl; a small tubercle situate on thc posterior sicle of thc teeth, unclcr thc areola, in thc right valvc, with an inclentation in the oppositc one for its rcccption; margin finely crcnatcd. Found in thc Frith of Forth; south coast of Devon; ancl Bantry Ilay, Ircland. 9. VENUS FASCIATA, pi. XXXVI, f. 10. Clmcsina jicsciala, First Ed., pl. 20, f. 10; Venus jasciata, Dono,·an, V, pi. li0; Pcnnant, IV, p. 203; Turton, Div., p. 1-16, pi. 8, f.!); Flcming, p. 4'1i; Forbcs, p. 52; Maton ancl Rackctt, p. 80; Vc1111s JJ<tphia, Montagu, p. 110, Shcll subtriangular, strong, subcomprcssed; umboncs pro• minen!, ncarly central, sharp-pointcd, contiguous, ancl much turncd to thc anterior sidc, with a consiclcrably clongated, shal- low, ornte lunulc bcneath thcm, ancl cxtrcmely fine, longitudi- nally oblique stri:c; anterior sidc acutcly hollowccl, thc lcngth of thc lunulc, at the base of which the vah•cs are somewhat peakc<l; c-artilagc or posterior sicle nearly ílat, with a lancealate cleprcssion; surface plain, whitc, ycllow, _or orange, but n~ost commonly with severa! racliations of rcclcl1sh-brown, pale hlac, or rusty-brown, which are sometimos intcrruptcd, and beauti- fully mollled in some spccimens; with upwarcls of a clozen broacl, ílat, lransycrsc, rcílccted ribs, uncqual both in numbcr ami brca<lth, bcing narrowcd ami more acule al thc pos terior si<lc, somctimcs regular, ami ncarly cquidistant, at othcrs, arrangcd in thrccs, or pairs, ancl in some instanccs an intcr- vcning, narrow, sharp rib bctwccn thc sets; in~ide smooth, glossy, whitc, pale ílcsh-colour, or lilac, somctimcs with a brown mark at onc cncl; margins nrnch thickcned, ami fincly crenatecl. Length a lilllc more than SC\'Cn-cighths, but more conunonly only six-eighths of an inch. F ound on almost ali thc Dritish and Irish coasts, particularly thosc with a gravclly or clayey bottom. 10. VE1'US O\'ATA, pi. XXXVII, f. 11. Timoclect oi:ata, First Ed ., pi. 19, f. 11 ; Timoclca Pcn11m1tii, Lcach, MSS., p. 9; Vc1111s ovcila, i\Iontagu, p. 120; Pcnnant, IV, p. 97, pi. 56, f. 56; Maton ancl Hackctt, p. 85, pl. 2, f. ,1; Pe1111s Pc1111antii, Forbcs, p. 52; Cytlwrcc, oi:alcc, Flcming, p. 4,15, Shell suborntc, subcomprcssed, obliquc, ncarly cquilatcrnl; pale brown or ycllowish, frequcnlly mottlcd with rusty-brown; with strong, longitudinal, clivergcnt ribs, crossecl by fine, trans- Yerse stri::c, which proclucc tubcrcular clcvations on thc ribs, ancl give a bcautifully canccllat ed appcarancc to thc surfacc ; umboncs almost central, slightly inllcctccl, with a subcorcliform lunulc undcr thcm, which is somcwhat elcvatccl in thc centre; insidc glossy, \\'hite, somelimcs of a palo !lcsh-colom, bcing frequcntly pale purplc in the centre of thc vahes; margins slightly crenatecl. Lcngth Yarying from half an inch to thrcc- quartcrs. Found on most of thc Dritish ami Irish coasts. \Ve met with a variety of this specics in thc cstuary of thc Clyclc, in which the longitu<linal ribs \\'ere set in pairs. GENUS 11.-CYTIIEREA,-Lamarck. Shell cquivalvc, generally more or lcss cquilatcral or obtusely trigonal, an<l transverso or ovate; smooth, or variously striatecl; with thrcc or more short, cli vergcnt, cardinal l<!clh ; an<l one anterior, approximate, lateral tooth in both valvcs, situatc ncar the primary teeth; two remole, lateral, muscular imprcssions, unitcd by a pallial impression, which is interruptc<l by a broa<l, transverso sinus; ligamcnt externa!. l. CvTHEnEA CmoNE, pl. XXXVII, f. 2. Cytlierea Cliio11c, First Ed., pi. l !), f. 2; Lamarck, V, p. 566; Fleming, p. 444; Turton, Iliv., p. 160, pi. 8, f. 11 ; Pcmu Chione, Montagu, p. 115 ; Donovan, I, pl. 17 ; Maton and Hackett, p, 84 ; CMonc cocci11ca, Lcach, MSS., p, 8. Shcll strong, obliquely ovatc, subcompressc<l; covcrccl with a thick, extremcly smooth, glossy, chcstnut-colourcd cpiclermis, with a fcw conccntric wrinkles; more or lcss ra<liate<l with cleepcr colourccl chcstnut; umboncs obtusc, placc<l consiclcrably to one sidc, bcneath them a strong, large, cordiform lunule ; inside of a glossy, bluish-white; margins thick, rouncled, with a hollow bctwixt them whcn closcd; pallial imprcssions with a vcry broacl, transversc sinus, acuminated at the point. Length threc inchcs; brcaclth thrcc an<l thrce-quartl!rs, This very bcautiful shell inhabits the coasts of Dorsctshirc and Cornwall. Young shells are frequently of a beautiful, dcep rosy ílcsh-colour.