CARDIUM. 37 



mate and subequidistant, the front ones are very slightly 

 the more approximate and broader than the hinder ones ; 

 the posterior of the left valve is very small. 



Immature individuals are far more beautiful than the 

 adult, the epidermis being extremely thin and transparent, 

 permitting the livid red or flesh-coloured spots or speckles 

 to be distinctly visible ; their interior, likewise, is often 

 adorned with a dull crimson- coloured stain on each side of 

 the valves. The internal rib-like elevations of the ventral 

 margin are generally divided by a narrow groove. The 

 most magnificent examples we have ever beheld came 

 from Bantry Bay, and measured three inches in length and 

 two-and-a-half in breadth. The ordinary run of specimens 

 does not greatly exceed two inches in length, and one-and- 

 a-half in breadth. 



We have frequently examined and delineated the animal, 

 and have been favoured by Mr. Clark with his observations 

 upon it. It is shaped as the shell, oval, and thick, and 

 mostly of a white colour. The free edges of the mantle are 

 plain, without filaments, and of a reddish- white or red-flesh 

 colour, varying in intensity in different individuals, and 

 bordered by white. The closed posterior portion is clothed 

 with thick-set long filaments, either white, or pale yellow 

 or reddish-brown. These are continued upon the slightly- 

 produced sij)hons, which are white tinged with tawny near 

 their orifices, or pale-yellow with flaky spots and lines. 

 They are united at their bases, separate, and divergent at 

 their extremities ; the branchial tube is rather the shorter, 

 though wider than the other, and has its orifice encircled 

 by white cirrhi, about eight of which are longer than the 

 others, and between each pair are three smaller ones. The 

 anal siphon has a simple margin ; a few small dark-brown 

 dots surround the opening, which is furnished with a tubular 



