24 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [318] 
also quite stout in its proportions. The color is dull greenish, or bluish 
green, more or less tinged with red, and the surface reflects bright iri- 
descent hues; the large lamelle or gills (fig. 50) along the sides are green- 
ish anteriorly, but farther back often become bright red, owing to the 
numerous blood-vessels that they contain. It is a very active and vora- 
cious worm, and has a large, retractile proboscis, armed with two strong, 
black, hook-like jaws at the end, and many smaller teeth on the sides, 
(figs. 48,49.) It feeds on other worms and various kinds of marine 
animals. It captures its prey by suddenly thrusting out its proboscis 
and seizing hold with the two terminal jaws; then withdrawing the 
proboscis, the food is torn and masticated at leisure, the proboscis, 
when withdrawn, acting somewhat like a gizzard. These large worms 
are dug out of their burrows and devoured eagerly by the tautog, scup, 
and other fishes. But at certain times, especially at night, they leave 
their own burrows and, coming to the surface, swim about like eels or 
snakes, in vast numbers, and at such times fall an easy prey to many 
kinds of fishes. This habit appears to be connected with the season of 
reproduction. They were observed thus swimming at the surface in the 
daytime, near Newport, in April, 1872, by Messrs. 'T. M. Prudden and T- 
H. Russell, and 1 have 6ften observed them in the evening, later in the 
season. At Watch Hill, Rhode Island, April 12, I found great numbers 
of the males swimming in the pools among the rocks at low-water, and 
discharging their milt. This worm also occurs in many other situa- 
tions, and is abundant in most places along the sandy and muddy shores, 
both of the sounds and estuaries, burrowing near low-water mark. It 
occurs all along the coast from New York to the Arctic Ocean, and is 
also common on the northern coasts of Europe. 
With the last, in this region and southward, another similar species, 
but of smaller size, is usuaily net with in large numbers. _ This is the 
Nereis limbata, (Plate XI, fig. 51, male.) It grows to.the length of five 
or six inches, and can easily be distinguished by its slender, sharp, 
light amber-colored jaws, and by the lateral lamelle, which are gmalt 
anteriorly and narrow or ligulate posteriorly. Its color, when full 
grown, is usually dull brown, or smoky brown or bronze-color anteriorly, 
with oblique light lines on the sides, and often with a whitish border to 
each ring, which form narrow, pale bands at the articulations; pos- 
teriorly the body and lateral appendages are pale red, and the longita- 
dinal dorsal blood-vessel is conspicuous. The male, of which the ante- 
rior part is represented in fig. 51, differs greatly from the female in 
the structure of the middle region of the body, which is brighter red in 
color, and has the side appendages more complicated and better adapted 
for swimming. The females agree with the males very well in the form 
and structure of the head and anterior part of the body, but the middle 
region does not become different from the anterior, as in the male. 
Both sexes are often dug out of their burrows, under stones or in the 
sand, but in such places there are few males in proportion to the fe- 
