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

116 MOLLUSCA. [TUBICOLARIA, lance-shaped, longitudinal platc, joincd to thc mcmbranc by which the valvcs are conncctcd, extcncling to ncarly thc pos- terior extrcmity; thc basal margin is providecl \Yith an clon- gatecl, tcstaccous, acccssory platc, which scems to prevent thc Yalvcs from opcning, cxccpt at thc cxtremities; insidc smooth, white, wilh a short, longitudinal, roundecl rib, becoming more devcloped as it approaches the base, crossed by rough points. General length half an inch; breaclth three-quarters. Found on the Devonshire coast, burrowing in a piece of rottcn wood, and Dr. Turton found it in an ole\ yard-arm of a vcsscl driftcd ashorc at Ilrixham. Thc Pholades always per- foratc the wood across the grain, whilc the Teredo naval-is penctratcs thc wood with thc grain. FAMILY XI.-TumcoLAillA, Shcll containcd in a lestaceous shcalh, distincl from its vnlvcs, incrustcd entirely or in part in thc wall of this tubc, or projecling outwards. ÜENUS 48.- TEnEDO.-Linn:cus. Shell cquirnlvc, iucc¡uilatcral, ancl orbicular, wif.h a subulafc process in fronl, a11CI gaping at both sides; anterior opcning angular at the baclc, ami the posterior one 1:ounded in fronl ; an clongatcd, curved, tooth-like proccss emanates from the insidc, in both rnh·cs, profruding from the umboncs; anterior muscular impression situate u pon thc subulate process; this shell is placed on thc anterior cxtremity of a testaceous, acces- sory tube, which is secreted by the animal in ifs progress through woocl, alHI forms a lining to the perforatccl cavity, becoming graclually wicler as thc animal adrnnces, ami is fre- qucnlly furnished intcrnally with vaulted septa; aperturc of thc- lubc rouncl, a1HI posteriorly dividcd into a clouble Lube, which the animal has the power of closing by means of two palmate, sometimcs pcnnafcd opercu\a. l. Tmumo N,\VA1.1s, pl. L, f. 1, 1, 2, 3, 4, 5, G, i. Tel'l:do navalis, Firsl Ed., pl. 3, f. 1 ; i\lontngu, p. 52i; lb., Sup., p. i; Donornn, V, pl. 145; Turton, Biv., p. l•I, pl. 2, f. 1, 2, 3 ; Fleming, p. 55-1. Shell with the 1•ah·es triangular, ear-shnped hehincl, a1HI hemispherical when closed; one ,·ah·c with a cun-ecl clcnticle 011 Lhe margin at the umbonal rcgion; surfacc of thc valvcs ~tri,1ted in vnrious directions, cach with a triangular projeclion in frout, inclining a littlc inwards, ali(\ conforming to the angu- lar form of the rnh-c,, with a lcugthcncd, ílat, cnrvecl tooth, projecling inwanls under thc hingc, in the same manncr as the Pholacles ; this birnll'e is scatcd 011 the wicler cm\ of a thin white.' ílcxuous, b~ittlc.' 1_1carly circular, ami rather abruptl; ta¡,en11g tubc, wluch 1s mtcrnally proridccl with transvcrse scpt,c, rcaching half way acro,s the tube; insicle of the mires whitc; thc supplcmcntal ,·ah·cs scatccl 011 lhc insicle of the lube, a1H\ ncar the smaller encl are spal uliform, bcing con,•ex ext cr- nall~·, ami concarn internally; onc ene\ linear, clongatccl, ancl straight, the othcr truncated. l:ig. l 1, reprcsci1ts a ~cction of tl1e 1 1 f 1 ower Clll o the tul,c, s iewing thc concamcrated structure. Fig. 2 is an entirc lube, shcwing the bivalvo seatcd on its widcr cxtrcmity a. Fig. 3, 4, 5, di!fcrcnt views of the bivah•e. Fig. 6, 7, different vicws of thc spoon-shaped appendagcs, or opereules. 2, TEnED0 lllPENNA'l'A, Tereclo bipemwta, Turton, l3iv., P· 15 ; lb., Conch. Dict., p. 18 ,1, f. 38, 3!), 40; Flcming, p. 454. Shcll with the vah·cs car-shapcd bchind, ancl the auricles rcflecled; an obliquc rib 011 the margin, above thc leeth; somc- what Jargcr than thc last; lnbc thicker, stronger, ami destitute of thc interna! concamcratccl partitions; ami insleacl of thc spoon-shapcd valvas, provided with two very long, slcncler ap- penclagcs, somcwhat curved and fcalherecl on each side. found in drifted timber at Exmouth. 3. TEllED0 NANA, pl. L, f. 1,1, 15. Teredo nana, Turton, Biv., p. 16, pi. 2, f. G, i; Fleming, p. 455. Shell with roundecl valves, and deslitutc of amieles hehind; a strong, conic, oblique tooth 011 the margin, al the umbo; valves destilule of a joinled, interna!, longitudinal rili. Dia- meter not quite an eighth of an inch. Found burrowing in a piece of wood al Torbay. ·,1. TE!tEDO MAI.E0LUS, pi. L, f. 16. Tcreclo maleolus, Turlon, IliY., p. 255, pl. 2, f. l!); Flcming, p. 455. Shell with ear-shapecl vah·es behind, detachcd 011 thcir inter- na\ edge, with reflected auricles; accessorial rnlvcs mallct- shapccl, ami placed transvcrsely; anterior triangular proccsscs rc,motely slriaterl, anc\ fcw in number; tube consisting of a light calcarcous de"¡iosit on the surface of lhe chamber, with its termi11atio11 slightly scmiconcamerated; accessorial val\'cs ter- minal. Diamctcr a quarter of an inch. Found in rollen wood at Torquay. GENUS 49,-GAS'l'noc n,ENA.-Spcugler. Shcll cr¡uirnhc, incquilateral, somewhal \\"edgc-shapccl; ante- rior side roumlecl, whcn Yiewed in front, postcriorly acumi- nated, ali(\ gaping wiclely, its apcrlme being suborntc, all(I acule bchincl; hinge marginal ancl linear, dcstiLule of teeth, but in their steacl a small. laminaled nppcmlage, cmanating from the umbo, alliecl lo the samc tooth-like proccss in the gcnns Pholas; ligament externa!. This shell is cnclosecl in a tcslaccous, irregular, cl:tl'if'onn tube, situate at i[s broaclcr cxtrcmity; it is open aud allc1111atcd anteriorly, with an oblo11g, bilobate aperturc, which is ncarly subd iviclcd by a prnjecting ~epl11111 thal docs not quite rcarh acro,s the opcning; thcse sen-e for thc passagc of thc two tubcs of thc animal; the posterior ell(l of thc t11be i, doscd. Thi, club-shapc<I Lube is fo1111d cithcr within thc perforatcd Ca\'ities of rocks, or in old shclls or corals, thc tcstarcous tuhc always prolru<ling bcyoncl the surfacc. l. GAS'l'HOCll iE:-;A P1101,,\DIA, pi. XLYllf, f. l:l, 1-J. Gastrocl1a:1w modiolin(I, First E<!., pi. !l, f. ¡;¡, 1 .¡; 1lf.3/a Ph~lruli(/, l\fo11tag11, p. 28 ali(! :,:,!); lb., Sup., p. 20 ; 1f.1¡11 cluúw, Pcnnant, IV, p. 82, pi. •l-1 , f. 19; Do1101·n11, II[, pi, 108 ; Turton, Ili,·., p. 18 ; G(ls/1'0c:l1r,·1w ltians, Fl<•mi11g, I'· -! ;1~ ; G'as- ti·oclwma c1111c[ful'lliis, Spcngler, Ir, i'· 1 i!), f. S, U, 1O, 1 l.