30 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [324] 
Under stones and decaying sea-weeds, near high-water mark, two or 
more kinds of small slender worms are usually found in great numbers ; 
these differ widely from all those before mentioned, and are more nearly 
related to the common earth-worms of the garden. One of these is white, 
slender, and about an inch long, tapering to both ends. This is Halodil- 
lus littoralis V., apparently forming a new genus allied to Hnchytreus, 
Another is of about the same size, but rather longer and more slender, 
and light red in color. It has a moniliform intestine, with a red blood- 
vessel attached to it above and below. It belongs apparently to the 
genus Clitellio, (C. irroratus V.) 
In addition to all these setigerous Annelids which have been enu- 
merated, there are quite a number of worms to be found on the rocky 
shores which are destitute of all these external appendages, and have 
the surface of the body smooth and ciliated. There are two tribes of 
such worms: in one of them the body is much elongated, and either 
roundish, or flattened, and usually very changeable in form and cap- 
able of great extension and contraction. These are known as Nemer- 
teans; most of them have a proboscis which they can dart out to a great 
length. In the other group, known as Planarians, the body is broad, 
short, and depressed, and often quite flat, and their internal structure 
is quite different. 
One of the largest of the Nemerteans, the Meckelia ingens, (Plate XIX, 
figs. 96, 96a,) is met with under stones where there is sand, but it be- 
longs properly to the sandy shores. Itis an enormous, smooth, flat worm, 
yellowish, flesh-colored, or whitish, and sometimes grows to be ten or 
twelve feet long and over an inch wide. The Meckelia rosea also occurs 
occasionally in similar places. This is similar in form, but is smaller, less 
flattened, and decidedly red in color. It is often covered by adhering 
sand. Another species, belonging to the Nemerteans, is often found in 
great abundance under stones from mid-tide to near high-water mark. 
Many of them are often found coiled together in large clusters. This'is 
the Nemertes socialis ; it is very slender or filiform, and often five or six 
inches long when extended. Its color is dark ash-brown or blackish, a 
little lighter beneath, and it has three or four eyes in a longitudinal 
group on each side of the head. Another larger species, apparently 
belonging to the genus Cerebratulus, but not sufficiently studied while 
living, is also abundant under stones. It is much stouter and is usually 
dark olive-green, brownish-green, or greenish-black in color, but a little 
lighter below and at the borders of the head. Several other small Ne- 
merteans occur under similar circumstances. In the pools, creeping over 
and among the alge and hydroids, a yellowish or light orange-colored 
species, one or two inches long, is often met with. This species secretes 
an unusual amount of mucus, which is, perhaps, connected with its 
climbing habits, and I have on this account named it Polinia glutinosa V., 
(Plate XIX, fig. 97.) It varies in the number of its eyes, according to 
its age, but they are always grouped in oblique clusters as in the figure. 
