101 



Figure. 



Cahdita laticostata. PL 35. Fig. 191. Shell of a richly varicoloured 

 species, with the left valve dropped to show the strong teeth of the 



hinge. 



Genus 3. CARDIUM, Linnceus. 



Animal ; suborbicular , tumid, its mantle freely open in front, with 

 plain or, less frequently, fringed edges, conspicuously fimbriated 

 in the neighbourhood of two very short, slightly -separated si- 

 phons, the branchial one of which is always fringed at the ori- 

 fice ; foot very large, cylindrical, geniculate. (Forbes.) 



Shell ; equivalve, rather inequilateral, mostly globosely ventricose, 

 heart-shaped, sometimes gaping behind, generally strongly ribbed, 

 the ribs being armed with scales or spines ; hinge composed of 

 two strong cardinal teeth in each valve interlocking crosswise, 

 and two distant lateral teeth, all of which, in some few species, 

 become partially or wholly obsolete. 



A genus abounding in shells of such exquisite varieties of form, colour, 

 and prickly sculpture as Cardium, is naturally one of great interest to 

 the collector ; even the British species, of which there are nine or ten, in- 

 clude two of large size and of very elaborate sculpture ; and among the 

 multitude of exotic forms the shells are truly beautiful. The animal has 

 a largely-developed foot, apt at burrowing or leaping, with a pair of short 

 fringed siphonal tubes pouting from the posterior united portion of the 

 mantle-lobes ; and, to judge from what passes on our own shores, is not 

 lightly esteemed as an article of food.* 



The foreign species of Cardium, numbering about a hundred and fifty, 

 have been drafted into sixteen genera and subgenera, of which the 

 following may be regarded as types : — C. costatum [Cardium proper), C. 

 Belcheri [Bucardiwm, Gray), L. Panamense [Trachy cardium, Morch.), C. 

 aculeatum [Acanthocardia, Gray), C. edule [Cerostoderma, Poli.), C. Grcen- 

 landicum [Serripes, Beck.), C. ringieulum [fapijridea, Swainson), C. bul- 

 lata [Fidvia, Gray), C. lavigatum (Lavicardhtm, Swainson), C. cardissa 



* Cardium edule, the edible Cockle of the London market, gives place as an article of food 

 to the larger C. echinatum in some parts of the country. Turton describes this latter species as 

 being collected in great abundance on the Paignton Sands in Torbay, " where at low spring-tides 

 they may be observed with the fringed tubes appearing just above the surface. The neighbour- 

 ing cottagers gather them in baskets and panniers, and after cleansing them a few hours in cold 

 spring water, fry the fish in a batter made of crumbs of bread, producing a wholesome and sa- 

 voury dish. The inhabitants call them red-noses." — Conch. I)ilh. Lis. Brit., p. 1S3. 



