94 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [388] 
common Teredo, except that it has long, oar-shaped pallets, with slender 
stalks; the blade is flattened on the inside and convex externally, and 
consists of ten to twelve, or more, funnel-shaped segments which set 
one into another; their margins project at the sides, making the edges 
of the blade appear serrated. This species appears to be indigenous 
on this coast. It has been found living in a sunken wreck in Long 
Island Sound, near New Haven, and I have also taken it from the oak 
timbers of a vessel, the Peterhoff, employed in the blockading service, 
during the late war, on the coast of the Southern States. It grows toa 
rather large size, often forming holes a foot or more in length and a 
quarter of an inch in diameter, though usually smaller. The pallets are 
sometimes half an inch long. 
Among the kinds of bivalve shells that do not bore in wood, there are 
but few species that commonly inhabit pilesof wharves. The most fre- 
quent of these is the common muscle, Mytilus edulis, (p. 307, Plate XXXI, 
fig. 234,) which sometimes adheres in large clusters. The common oyster, 
Ostrea Virginiana, (p. 310,) often attaches itself to the piles, but in such 
situations seldom survives the winter. 
Ascidians often occur in large quantities attached to the piles, at and 
just below low-water mark, and also on the under side of floating timber. 
They often completely cover large surfaces and spread over the barna- 
cles, hydroids, and alge, which have previously located. They grow 
very rapidly, attaining their full size during a few weeks in midsummer. 
The most abundant species are usually Molgula Manhattensis (p. 311, 
Plate XX XIII, fig. 250) and Cynthia partita, (p. 311, Plate XX XIII, fig. 
246.) At Wood’s Hole, on the piles of the Government wharf, in August 
and September, the Perophora viridis V. was exceedingly abundant, creep- 
ing over and covering up the other ascidians as well as the barnacles, 
hydroids, and alge. This is a compound or “ social” Ascidian, in which 
stolon-like tubular processes come out from the basal portion of the first 
individuals and run in every direction over the surfaces of objects to 
which they are attached, producing buds at intervals, which rapidly 
develop into little Ascidians like the old ones, and give out other 
stolons in their turn; thus they will very soon cover large surfaces, 
though each individual Ascidian is quite small. The body is com- 
pressed, broad oval, or more or less rounded iz outline, with a terminal 
branchial, and lateral anal orifice, both slightly raised on short and 
broad tubes. The body is attached to the stolons by a short narrow 
pedicle, and is usually not more than an eighth of an inch high. The 
color is bright green or yellowish green, and the integument is soft and 
translucent. 
On the piles of the same wharf, and associated with the last, was 
another compound Ascidian, Amarecium constellatum ; this forms solid 
gelatinous masses, with a smooth, convex surface, usually less than aD 
inch in diameter and about half an inch high, but often larger. The 
zovids, or individual animals, are quite small, long, and slender, and en- 
