Shell nearly three inches in length, and two in breadth; very solid, subrotund, opaque, with twenty-one or more broad ribs which radiate from the beaks, with knots or tubercles on them, which on the anterior slope are flat, and even wanting in young specimens, and on the posterior side are more pointed and rugged; the interstices between the ribs coarsely striated. Umbones prominent; beaks incurved. Ligament large, central tooth large, and the lateral teeth remote.
This large, handsome cockle is essentially a Mediterrancan species, and is rare and local in England. It is found on the Devonshire coast, at Paignton, and occasionally at Dawlish, and at certain times of the year, especially in the spring after a gale from the east, numbers may be gathered. On paying a visit to the Paignton sands, for the purpose of shell collecting, in the spring of 1862, the beach was quite strewn with broken single valves of this cockle, and there had evidently been quantities of live specimens washed up as well, as we met many persons returning home with their baskets heavily laden with them.
Cardium rusticum_Red nose cockle.
del. _ G. B. Sowerby, lith. Vincent Brooks,Imp.
Gardium rusticum varies in colour, from nearly white to a rich rufous-brown; sometimes there is a white band round the shell, and one of a dark chestnut-brown towards the margins. The colouring of the animal is most beautiful, the body being of a pink or pale vermilion, the mantle yellow or reddish, and the long foot of a most brilliant crimson. This foot terminates in a hooked point, and when stretched to its utmost is nearly four inches in length. It is by means of this organ that the cockle can bury itself in the sands, and also take those wonderful leaps of which we read in Mr. Gosse's interesting work, 'The Aquarium,' and again in his 'A Year at the Shore,' where he mentions that a specimen was seen to throw itself over the gunwale of a boat when laid on the bottom boards. Mr. Gosse states, in this latter work, that the mode of leaping is performed as follows : - "The long taper foot is thrust to its utmost, and feels about for some resisting surface, a stone, for instance, which it no sooner feels than the hooked point is pressed stiffly against it", the whole foot, by muscular contraction, is made suddenly rigid, and the entire creature, - mantle, siphons, shell, and all, is jerked away in an uncouth manner".
There is another cockle found also at Paignton, which is even more scarce than Cardium rusticum, viz. Cardium aculeatum; it is larger and not so solid, with long spines on each rib, and is of a pale brownish-pink or flesh colour. It is very good to eat. I have had splendid specimens sent to me, alive, from Paignton, in a jar, with seaweed; some measuring more than three inches in length, and two-and-a-half in breadth, and I have taken them myself at Langston Point, near Dawlish. The foot of the animal is long, and of a reddish-pink, but not nearly so vivid or brilliant in colour as that of Cardium rusticum. It is also an inhabitant of the Mediterranean.