[319] INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 25 
males. The males, however, sometimes occur swimming free at the 
surface in vast numbers. They swim with an undulating motion, and 
are quite conspicuous on account of the bright red color of the middle 
region of their bodies. Mr. 8. L Smith observed them swimming in 
‘this way, in the daytime, in August, at Fire Island, on the southern 
side of Long Island, where they oceurred in incredible numbers and 
were eagerly pursued by the blue-fish, which at such times would not 
take bait. We often caught them in Vineyard Sound, in the evening, 
at the surface, with towing-nets. These worms must, therefore, con- 
tribute largely to the food of many fishes. It is very common on our 
sandy shores us far south as South Carolina. A third species, Nereis 
pelagica, (Plate XI, figs. 52-55,) is abundant under stones farther north, 
but in this region is chiefly found on shelly bottoms, in the deeper wa- 
ters of the sounds. These three species of Nereis are called “ clam- 
worms” by the fishermen. Two large species of worms belonging to 
the genus Rhynchobolus (formerly Glycera) are ofteiu met with in bur- 
rows, in the mud beneath stones. These are pale reddish, deep flesh- 
colored, or dull purplish red, and rather smooth-looking worms, thick- 
est in the middle, and tapering to both ends. They have a large pro- 
boscis, armed at the ends with four black, hook-like jaws, and are re- 
markable for their rapid spiral gyrations. They belong more properly 
to the muddy and sandy shores, and will, therefore, be mentioned more 
particularly in another place. They are represented on Plate X, figs. 
43-46. Ophelia simplex occurs under stones at balf-tide, and below. 
The Marphysa Leidyi (Plate XII, fig. 64) is a large and handsome 
worm, occasionally met with under stones at low-water mark, but is 
more common on shelly bottoms in shaliow water off shore. It grows 
to the length of six inches or more, and its body is flattened, except 
toward the head, where it becomes much narrowed and nearly cylin- 
drical. It is yellowish or brownish red, and brilliantly iridescent. The 
branchie are bright red, and commence at about the sixteenth segment ; 
the first ones have only one or two branches, but farther back they be- 
come beautifully pectinated. There are six unequal caudal cirri, the 
lower lateral ones longest. It is furnished with powerful jaws, and is 
carnivorous in its habits. 
A small but very active worm, Podarke obscura V., (Plate XII, fig. 61,) 
is often found in large numbers beneath stones. These are dark brown 
or blackish in color, sometimes with lighter bands. They come out at 
night and swim at the surface in vast numbers. They are also often met 
with at the surface among eel-grass, in the daytime, in large numbers. 
A large and very singular worm, which burrows and constructs tubes 
in the mud and gravel beneath stones, is the Cirratulus grandis V., 
(Plate XV, figs. 80,81.) This is usually yellowish brown, dull orange, or 
ocher-colored, and is remarkable for the numerous long, flexible, reddish 
or orange cirri that arise all along the sides. Another very large and 
interesting worm, often associated with the last, both among and under 
3.V 
