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

PECTINIDEs.] MOLLUSCA. 73 Fonncl at Anglcsey, by Pcnnant; llfontagu mct with it at Falmouth ami Salcomb Bay, Dcvonshire; and I found it on thc Durham coast. It i~ doubtful whethcr this is not a mere varicty of P. obso- letus, m thc young condition. 10. PEC'l'EN srnuosus, pi. XXV, f. 2. Pectc1i sinuosus, First Ed., pi. 32, f. 2 ; Flcming, p. 384 ; Lamarck, IV, p, 175; Turton, 13iv., p. 210, pi. 9, f. 5; Forbes, P· 40 ; Osfrea sinuosa, :Maton a11Cl Uackett, p. 99 ; Br01m, Wernerian Mcm., p. 51'1; lb., Ency. Brit., p. 418; Ost1-e1, pusio, Pcnnant, p. 101, pi. ,lJ, f. 65; Donovan, pi, 34. Shcll 01•ate, with numerous, divcrgent ribs, of uncqual thick- ncss; undcr valvc convcx, adhcrent, and much distorted, from its partaking of thc form of the substance to which it adhcres, by which the whole of the ribs are, in general, obliteratcd, except towards the umbo ; upper valve more llat thau the inferior, and more or less sinuous like the opposite valve; its whole surface is covcrcd with foliated, spinous, or scaly ribs, but these are intcrrupted by the lransvcrse swellings ami depressions which traversc it, thcsc clistortions frequently giving an undulatcd appcarancc to the ribs; auricles large, in many spccimcns nearly cqual, in others they are small ancl irregular; colour variable, somctimes recldish-brown, orange, or yellow, and other specimcns are mottled and clouded with white. Length t.11·0 inches; breadth an inch and a half. Found on many of the English and Irish coasts. ·11. PECTEN SPIN0SUS, pi. XXIV, f. 8. Pecten spinosus, First Ed., pi. 33, f. 8; Pecten pusio, Tur- ton, Biv., p. 215, pi. 17, f. 2; Fleming, p,385; Hinnitcspusio, Sowerby, Zoo!. J ourn., III, p, 71. · Shell oblong-o,•ate, with about forty-two alternately highcr and lower ribs, thickly set with vaulted spines, and longitudi- ually striated; ears very unequal in size, and obliquely ribbed and spinous ; bcneath the superior car are fivc tooth-like Jaminre; uppcr valve less convex than the lower; colour various, being plain yellow, orange, or brown, and sometimcs cloudcd with brown or chocolate-colour. Length three and a half eighths of an inch; brea<lth somewhat more than two and a half cighths. I first found this on the Herc! Sands, at South Shields; \V. C. Trcvelyan, Esq., met with it at Scaton. It also occurs al Eyemouth, Berwickshire; and was found at Torbay, by Turton. · This specics has much the aspect of the young of P. va1·iu.s, but will at once be distinguishcd by its more clongated form, ami in the ribs being alternately higher and lower. 12. PECTEN JAMESONI, pi. XXV, f. 7. Pecten Jamesoni, Fol'bes, Wernerian Mem,, VIII, p. 58, pi. 2, f. l. Shell subequivalvc, suborbicnlar, with longitudinal, undulated plaits, striatccl; the plaits four or five; ears unequal. Length and breadth three-quarters of an inch. "Alliecl to the Pecten polymoi-plms of Bronn (Phillippi, p. 79, tab. V, f. 18, 21), but clilfers in severa! rcspects, cspecially in the inequality of the auriclcs, Thc longitudinal strire vary much in coarseness; t.he upper valve is somewhat larger than thc Jower; the auricles al'e ribbed and striated by lines of growth; thc longitudinal ribs or folds vary much in convexity, T aud are sometimcs acutely carinatcd. Thc colour is whitc, with a tinge of red, cspecially ncar t.he bcaks. Very distinct from any recorded British specics."-Porbcs, Dreclged at Butc, by James Smith, Esq., of Jordan Hill. 13. PECTEN LurnsnunGI. Pecten Landsbzwgi, Forbcs, Werncrian Mem., VIII, p. 58, pi. 2, f. 2. Shell subequivalve, suborbicular, radiatcd with very small, longitudinal, rugose strire, and crossed by regular, undulating, transverse strire; auricles uneqnal. Lcngth half an inch; brca<lth five-twelfths. "A very beautiful species, allied to Pecten obsolctus; first obscrved by the Rev. Mr. Lanclsborough, on the coast of Ayr- shire, afterwards clrc<lgecl by Mr. Smith, off the coast of Butc. In colour it resemblcs Pecten obsolctus, but is somewhat more triangnlar in form ; from that spccies, however, it is casily dis- tinguished by the lineations of its surface, which is adorncd by numerous regular minute rays rugosely striated, and crossed by regular undulated transverse, somcwhat distant stri;c, The rays on the uppcr surface al'e furnished with short, bl'oad, obtuse spines, crowning the co1wex llexure of the unclnlated strire; the spines only cxist towarcls the margin on the lowcr valve. Thc rugose appearance of the longitudinal stri:c is caused by the intersticcs being punctate."-Porbes. 14. PECTEN GLADEn, pi. XXV, f. 3, 4. Pecten glabcr, First Ed., pi. 32, f. 3, 4; Pennant, IV, p. 102, No. 68; Montagu, Sup., p. 59, pi. 28, f. 6; Fleming, p, 384. Shell rather compresse<l, nearly smooth, with extremcly minute, concentric strim, visible only by the aid of a strong lcns; with seven ncarly obsolcte, rounded ribs, and intermc- diatc longitudinal stria}; surface mottle<l with red<lish-brown an<l yellow, sometimes plain; ears large, nearly cqual, thc one reticulated, thc other only striated; inside with twenty-one slender rays, the sixteen middle oncs arranged in fours, the two middle series approximating, filling the intervening hol\ows bctwecn the outcr sulci; inside same colour as thc outside, but palcr, exccpt near the hinge. Length thrce-quarters of an inch ; breadth somewhat less. Found at Anglesey, by Pennant, an<l in the Frith of Forth, at Dunbar, by Captain Laskey. 15. PECTEN S!MILIS, pi. XXV, f. 5, 6. Pecten similis, First Ed., pi. 32, f. 5, 6; Laskey, Werncrian Mcm., I, p. 387, pi. 8, f . 8; Fleming, p. 385. Shell subcomprcsscd, thin, smooth, scmitransparcnt, clouded with brown; ears unequal; under si<le more promincnt than the upper. Found in the Frith of Forth, by Captain Laskcy. 16. PECTEN TUMIDUS. Pecten t·i,midus, Turton, Biv., p. 212, pi. 17, f. 3; Fleming, p. 384. "Shell equivah•e, incquilateral, quite smooth, with one of t.hc sidcs pro<luce<l; a quarter of an inch in diameter, orbicular, glossy white, transparcnt, and without strire, ribs, or marks of any kind; the si<les not equal, in conscquence of one of them being prominent in a rounded manner; ears ncarly equa1.' '- Turton. Taken from the Serpula tabula1·ia, at Torbay, by Dr. Turton,