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

PnYU,IDIACEA.] MOLLUSCA. 67 colour nrions, dark chocolate-brown, burnt terra-sienna, or yellowish-white, with cloucls, strcaks, or spols. Lcngth not quite half an inch; brcadth somewhat more than half its length. This shell has much thc general appcarancc of the former spccics, but its marginal lecth suflicicntly charactcrisc it as dis- tinct. Found at Oban ami Appin, on thc Argylcshirc coast, but is very rare. Thc hanclsomc specimcu from which I clrcw fig. 21, was sent me by Captain Carmichacl. Sectfon I I I.-i1farghwl ligament smooth. 13. C111TON L,EVIGATUS, pi. XXI, f. 1 ami 16. Chiton la tus, Firsl Ed., pi. 35, f. l and 16; Chiton lteviga- tus, Flcming, Edin. Ency., p. 103; Lowe, Zoo!. Journ., II, p. 103, pi. 5, f. 6, 7 . Shcll oblong, broad, somewhat wider behind than bcfore, ancl slightly carinatcd; valvcs smooth, shining, and bcaked, with minute granulations; marginal ligament quite smooth, simple, with a very short and in<listinct fringc ; first valvc with ninc broad tee th, an<l thc terminal one with eight broad tceth; colour gcnerally dark reddish-olivc, ancl mottlecl with a paler lme, in othcrs approaching to clark slatc-colour, ancl somctimcs redclish-brown. Lcngth somewhat more than an inch; brcaclth three-fifths of its lcmgth. In the character of the marginal tecth, this shell approaches that of C. rnbe,·. Foun<l by :tlfr. Lowe, at Oban, Argyleshire, on the uncler sidc of loose rocks, which are only uncovered at Spring tides, about fifty yarcls south of the Custom I-Iouse, ancl also at Appin, by Captain Carmichael, who sent me thc spccimen from which fig. l was drawn. Fig. 16 was taken from a specimen founcl by my late friend Mr. Hancock, of Newcastlc-upon-Tync, bclow Tyne- mouth Castlc, in 1809; so that he was the discovcrer of the spccies. It was foun<l plentifully in Zetlaml ancl Loch l3room, by Dr. F leming. S eclion IV.-Doubtful species. 14. C11JT01' DISCORS. Chiton cliscoi·s, Maton an<l Hackett, p. 20; Chiton seplt:-m- valvis, Montagu, P· 3. "\Vith seven cnrinatcd valvcs, strongly benkccl; thc lh·c middle oncs divicled transversely from the anterior b:tse to the bcak, the hinder compnrtmcnt vcry fine shagrecn, the other very smooth, or faintly striated transvcrsely; the extreme vah-c at each en<l rufous-brown, the rest generally dark cinercous; bcaks frequently rufous; margin moderately broacl, ami finely reticulatcd; shape of C. hevi~·. Length hnlf an inch. "Found in Salcomb Bay, but rare."-1lfo11tagu. Whcther this is a <listinct species, it is dinlcult to determine; although I think in ali probability it is, as well as thc following species, lusus natw·m. Montngu, in his Snpplcment, says, "we are inclinecl to bclieve this an accidental variety of C. mm·- ginatus." 15. CHITON QUINQUEYALVIS, pi. XXI, f. 22. Chiton ·quinquevcilvis, First Ed., pi. 35, f. 22. Shell oval, carinate<l, of a re<ldish-gray; wit.h five considcr- ably beakecl valves, covcred with strong, shagreen-likc papilli; valres dividcd on each side by a dccp groove, inclining obliqnely from the llat cdgc lowarcls thc beaks, where the groovcs termí- nate; margin rathcr broacl, coverecl with extrcmely fine, irregu- lar, shagreen-likc papilli, with the cclge ciliatccl. Length thrce and a half cighths uf an inch; brcaclth threc-cighths. Found at Tenby, by General l3ingham.