s-. 



5. Cardium zonatum, pi. XXXV, f. 8. 

 Cardium zonatum, First Ed., pi. 22, f. 8. 

 Shell nearly globular, thin; with numerous, longitudinal 



ribs, crossed by close-set, scale-like processes ; the umbones 

 nearly central, and obtuse; external surface pale gamboge- 

 vellow, or sulphur-colour, with pretty broad, transverse bands 

 of dull green, sometimes with purple bands ; inside white, 

 linked with purple; cardinal teeth large, and acute. Diameter 

 not an inch. 



This species was first detected by my late friend Mr. Han- 

 cock, of Newcastle, at Seaton, in Yorkshire, and afterwards by 

 my late friend Dr. Goodall, Provost of Eton College, on the 

 Devonshire coast; and I was lately furnished with specimens by 

 Hobcrt Ball, Esq., of Dublin Castle, who obtained them at 

 Youghal, Ireland. 



This may be distinguished from the young of C. edulc, by 

 being invariably much thinner, and more inflated; smoother, 

 and its colour of a gamboge-yellow, and zoned. Its habitat is 

 at the mouths of rivers, where the water is brackish ; and it 

 never reaches an inch in diameter. 



6. Cardium fasciatum, pi. XXXV, f. 9 and 11. 



Cardium fasciatum, First Ed., pi. 22, f. 9 and 1 1 ; Mon- 

 tagu, Sup., p. 30, pi. 27, f. 6; Turton, Biv., p. 189; Fleming, 

 p. 422. 



Shell suborbicular, subtruncated on the posterior side, thin, 

 and subpellucid ; with about twenty-seven flat, smooth ribs, 

 which are slightly tuberculated at the rounded side ; colour 

 reddish-white, with three or four bands of reddish chestnut- 

 brown, penetrating to the inside of the shell, which is of a fine 

 bluish-white ; the ribs are also visible. Diameter seldom ex- 

 ceeding three-eighths of an inch ; breadth somewhat more. 



This shell will readily bo distinguished from the young of C. 

 edule, by its lateral subtruncation ; the young edule being inva- 

 riably circular in this condition. 



Found on the coasts of Cornwall, Devonshire, and Forfar- 

 shire. 



7. Cardium exiguum, pi. XXXV, f. 10. 



Cardium exiguum, First Ed., pi. 22, f. 10; Montagu, p. 82; 

 Turton, Biv., p. 186; Fleming, p. 422 ; Cardium pygmceum, 

 Donovan, I, pi. 32, f. 3. 



Shell very convex, subtriangular, and slightly cordiform ; 

 colour cream-white, or rosy ; with from twenty to twenty-two 

 strongly tuberculated ribs ; the intervening furrows deep and 

 transversely striated ; anterior side considerably sloped, and 

 nearly parallel with the umbones; inside smooth, white, and 

 sometimes reddish at the flattened side; margin deeply denti- 

 culated. Diameter about half an inch. 



The subtriangular form of this shell is one of its most striking 

 characteristics. 



Inhabits the coasts of Falmouth, Salcomb, and Torbay, where 

 Dr. Turton says he has found them burrowing in the hardest 

 stone ; also in the Frith of Forth ; Portmarnock, and the 

 Western coasts of Ireland. 



8. Cardium uevigatum, pi. XXXV, f. 12, 13, 14, 15. 

 Cardium Icevigatum, First Ed., pi. 22, f. 12, 13, 14, 15; 



Montagu, p. 80; Donovan, II, pi. 54; Turton, Biv., p. 190; 

 Fleming, p. 422; Forbes, p. 4G.' 



Shell elongated, subcompressed, suboval ; with numerous, 

 smooth, flat, narrow ribs, which become obsolete on both sides 



MOLLUSCA. [Concha cea. 



of the shell, divided by very narrow, shallow furrows, and cros- 

 sed by shallow, irregular, indistinct, concentric wrinkles; surface 

 of a pale yellowish tlesh-colour, frequently mottled with chest- 

 nut, covered by a yellowish-brown, or fawn-coloured epidermis, 

 frequently decorticated towards the umbones; inside smooth, 

 glossy, white, with the margin pretty deeply denticulated, with 

 indications of the ribs towards the base of the valves. Ordinary 

 length from two to two and a half inches ; breadth about from 

 one and three-quarters to two inches. 



In Orkney it attains the length of three inches. The speci- 

 men from which f. 12 was drawn is from that locality, and is in 

 the cabinet of William Nicol, Esq., of Edinburgh. 



In the earlier stages, this shell is of a rich chestnut, very 

 glossy, and with beautiful clouds and spots of rose-colour, and 

 the inside of a rosy hue, as in f. 15. 



9- Cardium oblongum, pi. XXXV, f. 16, 17. 



Cardium oblongum, First Ed., pi. 22, f. 16, 17; Brown, 

 Ency. Brit., 6th Ed., VI, p. 409, pi. 152, f. 9 ; Cardium sulca- 

 tum, Lamarck, VI, pt. 1st, p. 10; Ency. Meth., pi. 298, f. 5; 

 Wood, pi. 54, f. 3. 



Shell elongated, oval, oblique, considerably inflated; beaks 

 small ; with numerous, flat, narrow ribs, crossed by indistinct 

 lines of growth ; colour pale flesh, or reddish-buff, covered by 

 an olive or yellowish-brown epidermis ; inside glossy, white, 

 flesh-coloured, or pale lilac, crenulated at the margins, with the 

 ribs extending nearly half way from the base. Usual length 

 about an inch and a half; breadth nearly two inches. 



This shell will be easily distinguished from the C. lavigatum, 

 by its more lengthened form; being more oblique, considerably 

 more inflated, and in the ribs more numerous. 



Inhabits the coast of Bray, Ireland ; and at St. Andrew's, in 

 Scotland, where it was obtained by Dr. Coldstream, of Leith. 



Family IV — Conchacea. 



With at least three primary teeth in one valve, and the same 

 number for the most part in the other; in a few instances less. 



Genus 9 Pullastra Sowerby. 



Shell equivalve, transverse, inequilateral, the anterior side 

 being the shorter; three diverging cardinal teeth in both valves, 

 situate near to each other, and generally with a notched or cleft 

 termination ; and in a few species the central tooth is deeply so ; 

 two lateral, somewhat rounded, muscular impressions in each 

 valve; pallial impression with a large sinus ; ligament external, 

 and partly concealed by the dorsal margins of the valves. 



1. Pullastra decussata, pi. XXXVII, f. 5, 6. 



Venus decussata, First Ed., pi. 19, f- 6, 7; Montagu, p. 124; 

 Donovan, II, pi. 67; Turton, Biv., p. 158; Maton and Racked, 

 Linn. Tr., VIII, p. 88, pi. 2, f . 6 ; Venerupis decussata, Fle- 

 ming, p. 451. 



Shell suboval, transversely elongated, subrhomboidal ; ante- 

 rior side slightly truncated ; whole surface with strong, longitu- 

 dinal, and transverse stria;, producing a beautifully decussated 

 appearance, which is stronger at the anterior side ; umbones 

 blunt, with a lancealate, cordiform lunucle under them ; colour 

 of a pale or dark buff, with beautiful, irregular markings of deep 



