44 
EDIBLE BRITISH MOLLUSKS. 
very delicate; minute substances being dropped into 
tbe orifice of the mantle instantly excited the animal, 
and a column of water strongly directed, expelled 
them from the shell. With so much strength was the 
water in some instances ejected that it rose above the 
surface of three inches of superincumbent fluid. . . . 
Locomotion very confined; it is capable, with the assis- 
tance of its foot, which it uses in the same manner (but 
in a much more limited degree) as the Cardiacea, of 
fixing itself firmly in the sand, generally choosing to 
have the umbones covered by it, and the orifices of the 
tubes of the mantle nearly perpendicular.^^* 
Resting in this position on the margin of a sand 
bank of which the surrounding soil is mud, at too great 
a depth to be disturbed by storms, the Isocardia of our 
Irish Sea patiently collects its food from the surrounding 
element, assisted in its choice by the current it is capa- 
ble of creating by the alternate opening and closing of 
its valves.^^ 
The Mediterranean species of this bivalve are smaller 
than those found on our coasts, and there are no less 
than ‘‘^five or six kinds known in the European and 
Indian seas.'^f 
Epicharmus, in his play of the Marriage of Hebe,^ 
mentions shell-fish of all kinds, and says : — 
“And bring too tlie black 
Cockle, which keeps the cockle-hunter on the stretch.” J 
This may possibly refer to the oxhorn -cockle. 
The wife of a coastguard sman who had lived many 
years at Brixham, and had often luxuriated in a dish of 
* Brit. Conchol., by JeflPreys, vol. ii. pp. 300, 301. 
t ‘ Manuel de Conchy liologie,’ par le Dr. J. C. Chenu. 
J Athenseus, Bohn’s Class. Lib. b. iii. p. 142. 
