1 10 PHOLADID.E. 



A stunted variety is found, which is abbreviated poste- 

 riorly, and has its beak narrow, and peculiarly promi- 

 nent. Its striae, too, are so crowded as to present no 

 interstices. 



This is by far the largest of our British Pholades, the 

 shell attaining to five or six inches in length, and one and a 

 half in breadth. The number of the accessory plates, and 

 the possession of dorsal cells, are its salient characteristics. 



"Animal elongated, subcylindrical, pale -bluish white, 

 having the mantle closed throughout, except a passage in 

 the anterior ventral range for an oval foot, with a thick, 

 fleshy, subcylindrical base. The mantle posteriorly is pro- 

 longed into a very long, thick, rounded tube, which termi- 

 nates in two orifices, whereof the branchial one is the 

 largest, having from ten to fourteen large rays, each of 

 which have three, four, five, six, or seven cilia on one side ; 

 besides the principal rays, there are between each one or 

 two minor ones. The anal, or upper tube, is short, just 

 separate at its extremity from the branchial one, curves a 

 little upwards, and has its orifice plain. This tube is emi- 

 nently contractile, capable of great extension ; sometimes 

 to double the length of the shell, sometimes it is shortened 

 and inflated with water to a diameter as great, or even 

 greater, than the thickest part of the shell. When con- 

 tracted it has a corrugated aspect ; when extended it is of 

 a pearly-white colour, with the orifices and rays dusky. 

 For an inch or two towards the extremity it is papillose, 

 the papillte so disposed as to have a squamous aspect." — 

 Clakk's 3ISS., communicated hy Mr. Jeffreys. 



On the south coasts of England it is not only the com- 

 monest species of the genus, but one of the most abundant 

 of shells, being found in profusion near low-water mark, 

 imbedded in chalk, red-sandstone, lias, decaved wood, and 



