Qapers, Piddocks, and Ship-worms 167 



a central o-roove. The animal is wliite, tinofed with 

 brown ; the siphons longer and more slender in pro- 

 portion than in the Common Piddock, 

 and longitudinally grooved within. It is 

 a very sensitive creature, and readily 

 takes alarm, retiring into its chamber. 

 It is about 2f inches long. 



The Little Piddock (P. jyarvcC) has a 

 more solid, less convex shell than the 

 last, and is traversed by many rows of 

 overlapping scales, chiefly on the fore- 

 part of the valves, gradually getting less 

 towards the middle, and scarcely evident 

 behind; often stained with red from the 

 clay and red sandstone in which it is found. The 

 beaks are much nearer the centre than in the other 

 species. The hinge - plate is fur- 

 nished with a knob, apparently to 

 prevent the valves coming too close 

 together at that part. As in the 

 White Piddock, there is but one 

 dorsal shield, and this is of similar 

 pattern to that of P. Candida. It 

 is a south coast species, and has 

 been found also in Guernsey, 

 Dublin Bay, and near Belfast. Its length is about 

 2 inches. 



The Oval Piddock (P. crispata) has the shell oval 

 instead of oblong as in the other species; convex, 

 solid, coarse-looking, with a broad furrow extending 

 from the beak to the lower margin almost in the 

 middle of each valve. In front of this furrow there 

 are about 20 rows of overlapping sharp scales. The 



Little Piddock 



