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

92 MOLLUSCA. [CoNCHAC&A. 2. CYTHEREA MINIMA, pi. XXXVII, f. 3. Cytlie1•ea mi11ima, First Ed., pi. 19, f. 3; Cyp1·i11a mínima, Turton, Div,, p. 137; Fleming, p. 444; Ve,ms mi11imct, Mon- tagu, p, 121, pi. 3, f. 3; Maton and Rackett, p. 81. Shell strong, thick, suborbicular, a little compressed; um- boncs prominent, acute at the point,, and a little turned to one side ; outer surface wilh broad, concentric stri..e ; of a dclicatc flesh-colour, ami very glossy, with two white, cliver- gent, pretty broad lines, which cmanate from the umbones, and reach half way ·down the disks, like the lcttcr V; at the cxlremity of each line is a red streak, <liverging outwarcls to the margin; in some specimens, howevcr, this is wanting; but ali of them haYe spots ncar the margin; inside glossy, white; margin plain. Length a quartcr of an inch; breadth some- what more. Inlrnbits the harbour of Fahnouth. 3. ÜYTIIEREA MINUTA, pi. XXXVII, f. 4. Cytlm·ca min1tta, First Ed., pi. 19, f. 4. Shell ncarly orbicular, thick, glossy ; of a deep fawn-colour, an<l widc-set, concentric stri..e; with two whitc lines, cmauating from the umbones, and di,·erging to the base of the valves, in the form of the letter V; insicle glossy, and of a pale pink; 111argi11s smooth. Diameter threc-eighths of an inch. I found a siuglo specimon of this shell on thc beach ncar Dunbar, wilh tho animal in it, but in a Ycry decayc<l con- clition. This shell clilfcrs from thc precc<ling spccies, in being nearly orbicular, ati<l in the triangular lines reaching to the base. GENUS J2.- AnTEM1s.-Poli. Shell nearly orbicular an<l lenticular, exlernally atlCI conccn- trically groo\'Cicl; beaks much lurned to one siclc, bencath them a shorl, slrongly markecl, cordiform lunnlc; three cardinal tecth in each ,·alve, two of which are coutiguous, and thc other divergent ancl broacl in the right rnh'e, cleft in the centre, lo reccive that of tite opposite \'alve, wltich is slencler, with a , small, lateral, closely approximatccl tooth; pallial impression with n ,·cry largc, clecply clefinccl, wellge-shapecl, obliquely ascemling, nenrly straight-sidecl sinus, rr.aching, in mosl species, two-thinls ncross the rnlYes; cartilage snhexternal. l. AnTEM1s EX0I,ETA, pi. XXXVI, f. 1, 3, 19, 20. E.t·olcta orbiculm·is, Fir,t Ecl., pi. 20, f. 1, 3, 19, 20; A ·rtc- mis e.ro/eta , Poli, II, p. L, pi. 21, f. 9, 1 O, 11 ; Forbes, p. 51 ; Venus e.role/a, :Montagu, p. 11 G; Donovan, II, pi. 42; l\Iaton :md nackett, p. 87, pi. 3, f. 1; Turton, Bh•., p. 162, pi. 8, f. í; C!Jlhc,·ca c.i·oleta, Lnmarck, V, p. 5í2, Shcll orbiculnr, lentiform, slrong, moderately com·ex; with numerous, close-set, filiform, regular, concentric striro, ancl mnny well dcfinecl, hollow lines of growth; anterior siclc pro- Yiclecl with a nenrly obsolele, longitudinal furrow; striro on !he disk, nnd ns far as tite umhones, smooth ami slightly clepressecl, but thiu, elernted, ami sharp on the sicles ; umbones small, approximaling, slightly prorluced, ami much turne<l to one sicle, bencath them is situatecl a considerably sunk, strongly clcfinecl, elongate<l, corcliform, closcly and longitudinally striatecl lunule; externa] surface of a cream-white, yellowish-brown, or pale fown-colour, frequently with two or three ycry broacl rays of rufous-brown, dilfering in degree of intensily in various speci- mens, somelimes the rays consist of an interrupted series of triangular spots, ami in some instances !he surface is nearly covered by zigr.ag lilac markings; insicle smooth, whitc, but not glossy, excepting the muscular alt(] pallial impressions; margins plain. Ordinary diameter of the shell an inch ancl three- quarters; but in tite Irish Channel it is not unfrequently mel with measuring two incites and a half. Tltis shell is subjecl to sorne varialion in depth, atlll when full grown the linc of junction of tite valves is undulated, exhi- biting a consiclcrablc twist in the seam. A variety of this shell was foun<l in lhe Frilh of Forllt, l,y my fricnd James Gerarcl, Esq., of Edinburgh, \\'ith the stri:c wicle-scl, elevale<l, and \'ery sharp. 2. AnTEMIS LINCTA, pi. XXXVI, f. 2 and 4. E ,i·olcta lincta, First Ed., pi. 20, f. 2 ami 4; Forbcs, p. 51 ; Venus lincta, Pultcney, Cat. Dorsct, p. 34; Venus e.i·oleta, vm·., Mnton ancl Rackett, p. Sí, pi. 3, f. 2; Cythercc, linctc,, Lamarck, V, p. 5i3; Cytl1c1'CC1 simmta, Turton, Biv,, p, 169, but not the figure. Shell lentiform, ncarly orbicular, slightly elongatecl, ancl mo- cleratcly tltick; with numerous, very fine, filiform, close-set, concentric striro, smooth, llattenecl, ancl wide on tite disk, ex- lending to the umboncs in tite centre of tite \'ah·es, eleYated, sltarp, and sublamcllar on the sides, ami numerous, hollow, clistinct ly clefinecl lines of growtlt, with a longitudinal, slightly ltollowed furrow on tite posterior sides; umbones a little pro- ducecl, approximale, muclt turned to one side, beneath wlticlt is a deeply defined, elongated, cordiform lunule, witlt excecdingly fine, obliquely longitudinal striro; !tinge line of the anterior side with a long, flattenecl, lancealate clepression, :rnd vcry fiue, lon- gitudinally oblique slriro; externa\ surface of a uniform pale yellowish-brown, or fawn-colom, sometimes of a lil•id hue; insicle wltite, but nol smootlt, cxcept the muscular and pallial impressions, togclhcr with the cntire of the broa<l space be- neath thcm; margins plain. Seldom exccecliug an inch and a half iu lengtlt. This shell is clistinguished from tite A. c:1:olclCI, by its more elongated form, ami more taper shnpe towards tite umbonal region; by thc much finer striro, being nearly double in num- ber, atl(I its uniform colour, being always devoicl of radintio11s or markiugs of any kind, and in the !tinge line ore r tite liga- menl being flattened; whereas the A. e.i·oletci scarccly exltibits any appearance of tltat character, tite twist of tite seam is also muclt lcss in degree. It is liable to considerable rnriation in length, and also in tite depth of the \'all'es. It i; common on most of tite British aucl Irish coasls, Turton has properly clescribcd tite species, but most errouc- ously gil'en a representation of its cougcne r, A. e.coleta. GENUS 13.-CvPRINA,-Lamnrck. Sltell ventricose, equivalve, incc¡nilateral, oblic¡ucly hcart- sltaped; umbones obliquely curYed ante riorly ; three cardinal teeth in each rnlve, approximated al their l,nses, ami di,·ergeut above; witlt a posterior, lateral 100th, remole from tite primary teetlt, elevalecl in the right rnh·e, a1tCI receiYing bet ween it mu! tite margin, tite long fbt tooth of tite opposite rnl\'C; externa! smface coYercd by a tltick, ltorny epi1lermis ; cach v.1h·e witlt