[821] INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 27 
twelve pairs of scales, but they are rough, and covered with small 
rounded or hemispherical tubercles; this is usually dark brown. The 
third species has sixteen pairs of smooth scales, and belongs to another 
genus. This is Harmothoé imbricata ; it varies exceedingly in color, but 
is usually grayish or brownish, more or less specked, blotched, or striped 
with blackish ; sometimes there is a black stripe along the middle of 
the back ; sometimes the general color is dark reddish. These three 
species of scaly worms all have a large proboscis with four powerful 
jaws at the end, and a circle of papille, as in figs. 40 and 41; they are 
carnivorous in their habits and rather sluggish in their movements. 
When disturbed they curl themselves up into a ball. They are very 
complicated in their appendages, and the spines and set of these ap- 
pendages are very curious in structure, when examined with a micro- 
scope. Notwithstanding their numerous sharp spines they are often 
devoured by fishes, and they frequently also fall victims to their more 
powerful companions belonging to the Nereis tribe, and are sometimes 
destroyed even by the apparently inoffensive Nemerteans. Adhering to 
the under sides of the rocks and stones there are several kinds of tubes 
constructed by annelids. One of the most common and abundant kinds 
of these tube-dwelling worms is the Sabellaria rulgaris V., (Plate XVII, 
figs. 88, 88.) This worm constructs firm and hard tubes out of fine sand 
and a cement secreted by special glands. These tubes are bent and 
twisted in various directions and are generally united together into 
masses or colonies, sometimes forming aggregations of considerable 
thickness and perhaps several inches or a foot across. The tubes of this 
worm are also common on the shells of oysters. Another very curious 
and beautiful worm, the Scionopsis palmata V., constructs much larger 
and coarser tubes out of bits of sea-weeds and shells, sand, small pebbles, 
and other similar materials; these tubes are long and crooked and 
attached for their whole length to the under side of rocks. The worm 
that constructs them has some general resemblance to the Amphitrite 
ornata, but is seldom more than three or four inches long and is usually 
darker colored, the color being generally reddish brown or dark brown, 
more or less speckled with white. There are only seventeen fascicles 
of setze on each side. The gills are only three in number, viz: an odd 
median one, much larger than the others, placed just behind the tentacles ; 
and a pair of smaller ones, but similar in form and just back of the first ; 
all three gills have a stalk or peduncle, and branch toward the end in a 
palmate or digitate manner, each of the divisions again subdividing. 
The gills can be retracted beneath a sort of collar which arises just be- 
hind them; their color is greenish, specked with white. The gills of 
this worm are very elegant in form, and quite unlike those of any other 
known species, both in position and form. Therefore it is necessary to 
establish a new genus for this species. It has been found from Vineyard 
Sound to New Jersey ; both among eel-grass in shallow water, and under 
stones. The Nicolea simples is a related species, with similar habits. 
tiv 
