Qapers^ Piddocks^ and Ship-zvorms 



157 



mantle iiii})re.ssion. The {unmal is pale yellowish 

 the mantle tinged with red, and its edges fringed 

 where not united. The siphons are distinct for the 

 greater part of their length, reddish ; and the purple- 

 red foot is club-shaped when extended 

 It lives in the sand of extensive bays 

 on the coasts of Hampshire, Devon, 

 Wales, and Ireland, at the limits of 

 low water. 



The Pod Razor (>S'. siliqiia) is known 

 in Scotland as the Spout-fish. The 

 shell is familiar enough to all who 

 wander across sandy shores after the 

 spring tide has receded, though it is 

 only the empty and mostly broken 

 valves they see. When full - grown 

 these shells are 8 inches lono; and 

 1\ inch broad. A glance at the exterior 

 of one of these valves is very instruct- 

 ive, for it shows at once in what 

 manner the shell is enlarged. In most ]jf|f||f \, 

 of the bivalves we have been considerino- 

 the concentric ridges point to the fact 

 that on three sides of the beaks the 

 shell-margins have been added to pretty ^°Jdu^ed7 

 equally ; or, if the ribs were more closely 

 crowded at the ends than towards the front maro"in 

 that less material was added to the ends than to the 

 lower edge. The lines on the shell of the Razor 

 show us clearly that the chief addition is made to 

 the hinder end of the valves, next to the lower 

 margin, very slightly to the upper margin. To the 

 front end scarcely any addition is made — certainly 



