[431] INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 137 
length and breadth, though small areas of rocks, gravel, and sand occur 
at various places. 
The special localities, indicated on the chart, where dredgings were 
made on muddy bettoms, not including the outside dredgings, are as 
follows: In Buzzard’s Bay, at line 67, b ; 68, a, b, @: 74, a,b; 75, a, b, 
c, d, e, f; in Hadley Harbor, at 10, a, b, c,d; in Great Harbor, at 17, 
b,c; 19, b; in Robinson’s Hole, at 78, a, b, ¢; in Vineyard Sound, at 
47, b,c. Numerous other dredgings were made on muddy bottoms in 
this region that are not indicated on the chart. 
In Long Island Sound numerous dredgings have been made by the 
writer, with Mr. 8. I. Smith and others, during eight years. These ex- 
tend from a few miles west of the entrance of New Haven Harbor to 
the Thimble Islands and Faulkner’s Island on the east ; and from the Con- 
necticut shore nearly across the sound. The greater part of these dredg- 
ings were on muddy bottoms, and generally in 3 to 8 fathoms of water. 
The following are some of the most common and important of the 
Crustacea living on these muddy bottoms: the spider-erab, Libinia can- 
aliculata, (p. 368,) L. dubia, (p. 368,) Panopeus depressus, (p. 312, Plate 
I, fig. 3,) P. Say?, (p. 312,) the “ blue-crab,” Callinectes hastatus, (p. 367,) 
Mysis Americana, (p. 396,) Ptilocheirus pinguis, (p. 481,) Unciola irro- 
rata, (p. 340, Plate IV, fig. 19,) Limulus Polyphemus, (p. 340.) Numer- 
ous tube-dwelling Amphipods, including several species of Ampelisca 
and genera belonging to the Lysianassine occur, some of them in great 
numbers, and also additional species of crabs and shrimps. All these 
are of special importance, because they furnish great quantities of food 
for the fishes frequenting muddy bottoms. 
Of Annelids numerous burrowing and tube-dwelling kinds are to be 
found, some of them in great abundance. One of the most abundant 
and conspicuous species is Nephthys ingens, (Plate XII, figs. 59, 60.) This 
worm burrows in mud of all kinds, even in that which is so filled with 
decaying vegetable débris as to be very fetid. It grows to the length 
of more than six inches, with a diameter of a quarter of an inch or more, 
though most of the specimens are about half this size. The body is 
whitish, with a red median blood-vessel, but the lateral appendages are 
dark and the setze nearly black. It is very active, and wriggles about 
energetically by undulating its body laterally, to the right and left; this 
motion enables it to burrow quickly, or to swim quite rapidly. When 
captured it is very apt to break off the posterior part of its body, 
but can reproduce it. 
The Diopatra cuprea (p. 346, Plate XIII, figs. 67, 68) is often abun- 
dant where the mud is somewhat firm; the dredge often brings up large 
quantities of the projecting ends of its large tubes, but the occupant 
usually escapes by retreating below the surface. The.two species of 
Rhynchobolus are also quite common, but R. dibranchiatus (p. 341, Plate 
X, figs. 43, 44) is generally the most abundant. The curious Travisia 
carnea V. is seldom met with, and, like Brada setosa V., appears to be rare 
