42 THE SHELL-FISH OF THE COAST. 



time to have been completely eaten through. It 

 seems not unlikely that some of the breakages in 

 the Holland dikes are to be attributed to weakness 

 caused by. this enemy to wood. The metal casing 

 of ships' bottoms has prett}' eflFectually stopped all 

 attack in this direction, and much the same result 

 has been obtained from painting wood with creo- 

 sote oil. 



The best-known species of ship-worm is the Te- 

 redo navalis, which appears to have been introduced 

 upon our coast from Europe; its calcareous tube 

 measures as much as two feet, or more, in length. 

 It breeds in middle spring, and the eggs are said 

 to be developed by millions from a single individ- 

 ual. The young are provided with eyes, which, 

 however, disappear in later life. Closely related 

 to this species is the form known as Xylotrya fim- 

 briata (PI. 2, Figs. 17, 18, 19), which differs mainly 

 in the outline of the minute stylets or ' pallets,' 

 which project from the posterior portion of the 

 siphonal tube. 



Another form of borer, much rarer with us than 

 in the North, is the Saxicava Arctica (PI. 2, Fig. 

 14), a small shell somewhat resembling the sand- 

 clam, which not infrequently attacks the softer lime- 

 stones. 



ITot the least interesting of our coast Mollusca is 

 an individual which has thus far escaped the clutch 

 of the epicure, but which, if delicacy of flavor counts 

 for anything, is not unlikely to gain a prominent 

 position on the table in the near future. This is 

 the razor or so-called razor-fish {Solen Americanus, 



