i6o Shell Life 



than young Pod Razors of .similar length, and it 

 inhabits deeper water, being found usually between 

 3 and 20 fathoms, but at Jersey and Plerm it occurs 



Sword Razor (slightly reduced) 



at low water. Linnasus regarded it as a variety of 

 ^. sillqua, and I think it very likely that he was 

 right. 



The Transparent Razor (>S^. pellucidus) is similar to 

 the last named in form, but with thinner though 

 scarcely transparent shell, and the hinge not quite so 

 near the end. Length about 1\ inch. It is very 

 doubtful whether this again is any more than a 

 juvenile form of S. siliqua. 



The Grooved Razor (S. vagina) resembles S. siliqua 

 generally, but is more cylindrical, quite straight, of 

 equal size from end to end, and possessing but 

 one cardinal in each valve, which is rounded and 

 stalked. Its English name is due to a constriction 

 at the fore-end " as if it had been tied while in a soft 

 and plastic state with a string" (Jeffreys), but this 

 constriction is frequently found in specimens that 

 otherwise agree with S. siliqua. I fear there is but 

 one British species of Solen, with several variations 

 from the t^'pical form. 



The Rock-borers (Saxicava) have the mantle 

 entirely closed, save for a narrow orifice to allow 

 the passage of the finger-like foot; the siphons are 

 long and partially united ; the shell gapes at each 



