[347] INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 53 
posing the curious bright red gills, which are shaped something like 
miniature fir trees. The central stem is long and tapering, with a blood- 
vessel winding spirally up to its summit, and another winding in the 
opposite direction down to its base; the basal part is naked, but above 
this slender branches are given off, forming spirals all along the stem 
and gradually decreasing in leugth to the tip; each of the branches con- 
tains two slender blood-vessels. These branchie commence at the fifth 
segment and do not extend tothe end of the body, the last ones being 
much smaller, with few branches. The first four setigerous segments 
have an acute, conical, papilliform ventral cirrus at the base of the lateral 
appendages; on the fifth and following segments these become low, 
broad, rounded, whitish tubercles, with longitudinal wrinkles or grooves, 
and with a dark spot in the middle; these appear to contain the glands 
which secrete the cement used in constructing the lining of the tube, for 
when attaching any additional object at the end, after adjusting it in the de- 
sired position the worm constantly rubs this part of the lower surface back- 
ward and forward over the edge of the tube and the object to be cemented 
to it, until a perfect adherence is effected, and a smooth coating of firm 
mucus is deposited, and this operation is repeated for every piece added 
to the tube. It is very interesting to watch these worms, when in con- 
finement in an aquarium, while engaged in constructing their tubes. 
By placing bits of bright colored shells, tinsel, cloth, or even pieces 
of bright colored feathers, near the tubes, they can be induced to use 
them, and thus some very curious looking tubes will be produced ; 
but they evidently prefer the more rough and homely materials to which 
they are accustomed, when they can be had. The iridescent, opaline 
colors of this species are usually very brilliant and beautiful, especially on 
the back, head, and bases of theantenne. The general color of the body 
is reddish brown, or deep brown, thickly specked with gray; the an- 
tenne are paler brown; the lateral appendages yellowish brown, finely 
specked with white and dark brown; the gills usually blood-red, but 
varying from light red to dark brown. There are two, small, black eyes 
between the bases of the odd median and upper lateral antenne. This 
species is often quite abundant on the sand-flats near low-water mark, 
especially where there is more or less mud mixed with the sand, but it 
is still more abundant in the shallow or moderately deep waters off 
shore, on muddy and shelly bottoms. It is difficult, however, to obtain 
entire specimens with the dredge, for it usually merely cuts off the up- 
per end of the tube, while the occupant retreats below; occasionally 
the head of the worm is cut off in this way. On the shore, also, it is 
not easy to obtain entire specimens unless the tubes be cautiously ap- 
proached and the retreat of the worm prevented by a sudden and deep 
thrust of the spade below it, so as to cut off the tube. This species is 
carnivorous and has a very powerful set of black jaws, which are une- 
qual on the two sides of the mouth, (fig. 68.) 
The Marphysa Leidyi (p. 319, Plate XII, fig. 64) is allied to the pre- 
