Cardiacea.] MOLLUSCA. 



Cor, Montagu, p. 134 and 578; lb., Sup., p. 50; Donovan, IV, 

 pi. 134; Laskey, Wernerian Mem., I, p. 385, pi. 8, f. 7; Brown, 

 Wernerian Mem., II, p. 511 and 535. 



Shell subglobose, much inflated, heart-shaped, strong; with 

 strong, irregular, transverse wrinkles, increasing in coarseness 

 and elevation as they approach the base of the valves ; covered 

 with a dark brown, or reddish-brown epidermis; umbones large, 

 greatly contorted, the beaks pointed upwards, much turned to 

 one side, considerably apart from each other, and a somewhat 

 hollowed space below them, on each side of the junction of the 

 valves ; inside dull yellowish-white, frequently tinged with pale 

 flesh-colour, and pale buff; surface of large specimens rather 

 uneven ; margins smooth, and sharp on the edge ; muscular 

 impressions strongly marked, that on the left side deep ; hinge 

 with very prominent teeth, standing above the level of the 

 valve ; in the right valve an erect cardinal and a longitudinal 

 tooth, fitting into deep sockets in the opposite valve, which is 

 provided with a double erect cardinal tooth. 



Found in Bantry Bay, Dublin Bay, and Cove of Cork, Ire- 

 land ; off St. Abb's Head, Scotland ; and is said to inhabit the 

 Hebrides. 



Genus 8. — Cardium Linnaeus. 



Shell equivalve, nearly equilateral, and more or less gaping 

 posteriorly ; generally with strong ribs, radiating from the um- 

 bones to the margins; inside of the lips crenulated, or dentated, 

 corresponding in size to the ribs ; two approximate, oblique, 

 cardinal teeth in both valves, locking into each other crossways, 

 and with two remote, lateral teeth in both valves; two lateral, 

 distinct, muscular impressions in each valve; mantle impressions 

 entire ; liagament external. 



1. Cardium aculeatum, pi. XXXIV, f. 1, 2, 3, 4, 5, 

 and 7. 



Cardium aculeatum, First Ed., pi. 21, f. 1, 2; Montagu, p. 

 77 ; Cardium ciliare, the young shell, Montagu, p. 79 ; Dono- 

 van, I, pi. 6 ; Fleming, p. 420 ; Turton, Biv., p. 180, pi. 13, f. 

 6, 7 ; Forbes, p. 45 ; Brown, Wernerian Mem., II, p. 508. 



Shell suborbicular, very convex ; anterior side rounded ; pos- 

 terior side subtruncated, produced at its lower marginal angle ; 

 with about twenty-one strong, longitudinal, square-sided ribs, 

 emanating at the umbones and terminating on the margins, 

 which are strongly scalloped, the termination of the ribs of one 

 valve locking into the base of the furrows in the opposite one ; 

 each rib with a central, longitudinal sulcus, in which are planted 

 numerous, short, compressed, arcuated spines, these are longer 

 and more acute on the sides of the valves ; outside of a yel- 

 lowish-brown colour, with transverse, distant, broad bands of 

 brown, and generally darker in the sulci, which are deep and 

 transversely striated; inside glossy, yellowish, flesh-coloured, or 

 purple, with flattened ribs, caused by the external furrows being 

 raised internally, the interstices between the ribs white, are of 

 a paler hue than the rest of the interior. Diameter nearly four 

 inches. 



Inhabits the South Devonshire coast ; Dowlish, Warren, 

 Torcross, the Hebrides, and Orkney Islands ; Dublin Bay and 

 Portmarnock, Ireland. 



Figs. 3, 4, 5, and 7, the young shell ; the latter is Cardium 

 ciliare of Donovan and Montagu. 



2. Cardium echinatum, pi. XXXIV, f. 6 and 8. 



Cardium echinatum, First Ed., pi. 21, f. 6 and 8; Montagu, 

 p. 78; Turton, Biv., p. 183; Fleming, p. 421 ; Brown, Wer- 

 nerian Mem., II, p. 509. 



Shell suborbicular, very convex; umbones nearly central; 

 with about eighteen longitudinal, somewhat wrinkled ribs, pro- 

 vided with a central series of numerous, close-set, convex 

 spines, the intervening furrows deep, and transversely striated ; 

 the base of the ribs of one valve locking into the intervening 

 furrows of the opposite valve ; colour rusty orange-yellow ; 

 inside white, glossy, sometimes slightly tinged with yellow. 

 Diameter two and a half inches. 



This shell differs from C. echinatum, in being more orbicular, 

 considerably less, the ribs rounder, the furrows more wrinkled, 

 the spines not so long, and blunt at the points. It is common 

 on all the coasts of Great Britain and Ireland. 



Fig. 8, the young shell. 



3- Cardium tuberculatum, pi. XXXIV, f. 9. 



Cardium tuberculatum, First Ed., pi. 21, f. 9; Lamarck, VI, 

 pt. 1st, f. 8; Montagu, p. 79 and 568; Donovan, III, pi. 107, 

 f. 2; Turton, Biv., p. 181 ; Fleming, p. 421. 



Shell strong, ponderous, nearly globular ; umbones large, 

 much inflected ; anterior side slightly flattened ; posterior side 

 well rounded ; surface covered with about twenty-one rounded 

 ribs, the anterior ones beset with short, rounded, blunt tuber- 

 cles, and the posterior ones a little scaly ; the intervening fur- 

 rows roughly and irregularly striate transversely ; colour of a 

 pale rusty-brown ; inside cream-white, with the ribs extending 

 only half way up from the base of the valves. Diameter nearlv 

 four inches. 



Inhabits the Sands at Falmouth, Cornwall, Paignton Sands. 

 Torbay. It is, however, a rare British species. 



4. Cardium edule, pi. XXXV, f. 1, 2, 3, 4, 5, 6, 7. 



Cardium edule, First Ed., pi. 22, f. 1, 2, 3, 4, 5, 6, 7; Mon- 

 tagu, p. 76; Turton, Biv., p. 188; Fleming, p. 422 ; Forbes, 

 p. 46 ; Cardium rusticum, Donovan, IV, pi. 124, f. 1,2. 



Shell yellowish-white, subglobose, oblique ; with about twenty- 

 six antiquated, longitudinal ribs, provided with numerous, trans- 

 verse, scaly processes, and wide-set lines of growth ; posterior 

 end a little elongated ; inside white ; the muscular impressions, 

 and produced side, frequently of a rusty-brown ; the internal 

 ribs reaching only about a fourth of the length of the shell from 

 the margins, which are deeply scalloped. 



This shell is common on almost all sandy shores in Great 

 Britain and Ireland. It frequently grows to a large size, par- 

 ticularly in Orkney, where it often attains nearly two inches 

 and a quarter in length. It is subject to considerable variety 

 in its contour. 



Figs. 5 and 6, the young shell. At the first stage it is nearly 

 orbicular, which will at once distinguish it from the C. fascialum 

 and C. exiguum. 



Fig. 2, the ordinary size of the shell. 



Fig. 1, drawn from a specimen found at Waterford, Ireland. 



Fig. 3, taken from a specimen obtained at the basin of Mon- 

 trose, where it is the ordinary form; the transverse scales of the 

 ribs of a reddish-brown. 



Fig. 4, a very beautiful, thin variety, found in Lough Strang- 

 ford, Ireland, generally of a rusty-brown colour. 



Fig. 7, Cardium rusticum of Donovan. 



