{349] INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 55 
similar places. But the worms are very unlike in appearance and 
structure. 
Several species of slender, greenish worms, belonging to the gen- 
era, Phyllodoce, Eumidia, Eulalia, and Eteone, are occasionally dug out of 
the sand. In all these the head is well-developed and provided with 
four anterne at the end, and in the three last with an odd median 
one on its upper side, and they all have two well-developed eyes, 
and oval or lanceolate, leaf-like branchie along the sides of the back. 
They are very active species, and most of them belong properly to 
the shelly and rocky bottoms in deeper water, where they are often 
very abundant. In sheltered coves, where there is mud with the sand, 
Cistenides Gouldii V., (p. 323, Plate XVII, figs. 87, 87a,) often occurs, 
but it is more partial to the muddy shores. On various dead shells, as 
well as on certain living ones, and on the back of Limulus, &c., the 
masses of hard, sandy tubes, built and occupied by the Sabellaria vul- 
garis V., (p. 321, Plate XVII, figs. 88, 88a,) often occur. 
Of the Nemerteans the largest and most conspicuous is the Jfeckelia 
ingens (p. 324, Plate XIX, figs. 96, 96a.) This species lives in the 
clear sand, near low-water mark, as well as in places that are more or 
less muddy, and notwithstanding its softness and fragility, by its means 
of burrowing rapidly, it can maintain itself even on exposed shores, 
where the sands are loose and constantly moved by the waves. The 
young, several inches or even a foot in. length, are quite common, but 
the full-grown ones are only occasionally met with. The largest that I 
have found were at least 15 feet long, when extended, and over an inch 
broad, being quite flat; but they co ild contract to two or three feet in 
length, and then became nearly cylindrical and about three-quarters 
of an iuch in diameter; the body was largest anteriorly, tapering very 
gradually to the posterior end, which was flat and thin, terminated by 
a central, small, slender, acute, contractile process one-quarter of an 
inch or less in length. The proboscis of the largest one, when pro- 
traded, was fifteen inches long, and about one-fifth of an inch in diame- 
ter whens thickest. This proboscis, which is forcibly protruded from a 
terminal opening in the head, appears to be an organ of locomotion, at 
least to a certain extent, for when it penetrates the loose sand in any 
direction it makes an opening into which the head can be thrust, and 
then, by enlarging the opening, it can easily penetrate. But the pro- 
boscis is probably used, also, a8 an instrument for exploring the sand 
in-various directions, either in search of food or to test its hardness or 
fitness for burrowing, thus economizing time and labor. At any rate, 
the ways in which this remarkable instrument is used by these worms, 
when kept in confinement with sand, suggest both these uses. But 
the proboscis is by no means the- ni ipal organ of locomotion, for the 
head itself is used for this purpose, urged forward by the undulatory 
movements of the muscular body, and aided by the constantly chang- 
ing bulbous expansions, both of the head and body, which both crowd 
