86 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [380] 
rows are nearly round, and of all sizes up to about a sixteenth of an 
inch in diameter, and they go into the wood at all angles and are 
usually more or less crooked. They are often so numerous as to reduce 
the wood to mere series of thin partitions between the holes. In this 
state the wood rapidly decays, or is washed away by the waves, and 
every new surface exposed is immediately attacked, so that layer after 
layer is rapidly removed, and the timber thus wastes away and is en- 
tirely destroyed in afew years. It destroys soft woods more rapidly 
than hard ones, but all kinds are attacked except teak. It works 
chiefly in the softer parts of the wood, between the hard, annual lay- 
ers, and avoids the knots and lines of hard fiber connected with them, 
as well as rusted portions around nails that have been driven in, and, 
consequently, as the timbers waste away under its attacks, these 
harder portions stand out in bold relief. Where abundant it will 
destroy soft timber at the rate of half an inch or more every year, thus 
diminishing the effective diameter of piles about an inch annually. 
Generally, however, the amount is probably not more than half this, but 
even at that rate, the largest timbers will soon be destroyed, especially 
when, as often happens, the Teredos are aiding in this work of destruction, 
It lives in a pretty narrow zone, extending a short distance above 
and below low-water mark. It occurs all along our shores, from Long 
Island Sound to Nova Scotia. In the Bay of Fundy it often does 
great damage to the timbers and other wood-work used in constructing 
the brush fish-weirs, as well as to the wharves, &c. At Wood’s Hole it 
was formerly found to be very destructive to the piles of the wharves. 
The piles of the new Government wharves have been protected by 
broad bands of tin-plate, covering the zone which it chiefly aftects. 
North of Cape Cod, where the tides are much greater, this zone is 
broader, and this remedy is not so easily applied. It does great dam- 
age, also, to ship-timber floating in the docks, and great losses are 
sometimes caused in this way. Complaints of such ravages in the 
navy-yard at Portsmouth, New Hampshire, have been made, and they 
also occur at the Charlestown navy-yard, and in the piles of the wharves 
at Boston. Probably the wharves and other submerged wood-work in 
all our sea-ports, from New York northward, are more or less injured 
by this creature, and, if it could be accurately estimated, the damage 
would be found surprisingly great. 
Unlike the Teredo, this creature is a vegetarian, and eats the wood 
which it excavates, so that its boring operations provide it with both 
food and shelter. The burrows are made by means of its stout mandi- 
bles or jaws. It is capable of swimming quite rapidly, and can leap 
backward suddenly by means of its tail. It can creep both forward 
and backward. Its legs are short and better adapted for moving up 
and down in its burrow than elsewhere, and its body is rounded, with 
parallel sides, and well adapted to its mode of life. When disturbed 
it will roll itself into a ball. The female carries seven to nine eggs or 
young in the inecubatory pouch at one time, 
