PHOLAS. 177 



covered with a thick red-brown epidermis, which is aspersed 

 with thick-set sand-like red eminences,, or minute papillae, that 

 become larger and more intense at the termini of the orifices, 

 where its margin is irregularly encircled with a fine light 

 brown fringe or rather pile; within the periphery of this 

 fringe are the siphonal apertures, the branchial one being 

 rather the longest, without cirrhi, but sinuated or escalloped, 

 and marked with a dozen brown and white alternate lines 

 running into the tube; these at half-contraction have the 

 appearance of short blunt cirrhi, occasioned by the doubling 

 of the brown and white points of the scallops, the two nearest 

 the anal tube being the longest in appearance, with a single 

 one exactly opposite the two; these however are only de- 

 ceptions, and vanish entirely when the tube is fully expanded ; 

 the anal cylinder is pale brown and perfectly simple ; both 

 siphons are destitute of cilia, having only the margins of the 

 sheath finely pilose ; none of the other Pholades are without 

 cirrhi on the branchial orifice. The foot, when at rest, is 

 nearly an oval, but in action it becomes pointed behind and 

 rounded in front ; it is truncate at the base, and fixed to the 

 body by a long round cylindrical fleshy pedicle of a pale 

 bluish-white colour. The branchiae and the palpi on each 

 side are so nearly similar to those of P. dactylus as to require 

 no observation ; the siphonal sheath when extended is double 

 the length of the shell. The liver is darker than in the last 

 species. 



P. CANDIDA, Linnaeus. 

 P. Candida, Brit. Moll. i. p. 117, pi. 4. f. 1, 2. 



Animal conically elongated from the anterior end to the 

 posterior axis of the cone. The body, sheath and mantle are 

 a pale red-brown, but when divested of the epidermis, of the 

 palest hyaline tinged with brown. The mantle as usual is 

 closed, except the aperture for the foot, and being produced 

 into a sheath that is proportionately shorter than in its con- 

 geners; the siphons are of the same length, and both are 

 cirrhated at their orifices, the only example in this respect 

 that we know of amongst the Pholades the branchial with 



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