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 pretty effectually 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 XYylotrya fim- 
briata (P|. 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 (Pl. 2, Fig. 
14), a small shell somewhat resembling the sand- 
clam, which not infrequently attacks the softer lime- 
stones. 
Not 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, 
