[415] INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 121 
the shells and pebbles or between the ascidians, &e., like many of the 
larger annelids, some of the crabs, and other crustacea, &c.; they may 
be species that live among or attached to the hydroids, bryozoa, aseid- 
ians, and alge which grow upon the shells and pebbles ; such are many 
ef the small crustacea, some annelids, many small gastropod shells, and 
most of the more delicate bryozoa and hydroids ; or they may be larger 
kinds that creep or swim about over the bottom, in search of food, such 
as the lobster, the larger crabs, hermit-crabs, large gastropod mollusks, 
star-fishes, sea-urchins, holothurians, &c. Owing to the great abundance 
of animal life on bottoms of this character they are the favorite feeding - 
grounds of many kinds of fishes, such as the tautog, seup, black 
bass, haddock, and cod, together with many others that are less valua- 
ble. Most of the “banks” and “fishing-grounds” resorted to by the 
line fishermen have either gravelly and shelly or else rocky bottoms, 
and those banks most frequented by fishes are almost always found to 
be rich dredging-grounds. The gravelly banks in this region are, in 
winter and spring, fishing-grounds for cod and haddock, but these fishes 
retreat to colder waters in the summer. 
Among the Crustacea the most abundant and important species are 
the lobster, Homarus Americanus, (p. 395,) the common shrimp, Oran- 
gon vulgaris, (p. 339, Plate ILI, fig. 10,) the common rock-erab, Cancer 
irroratus, (p. 312,) Panopeus Sayi, (p. 312,) P. depressus, (p. 312, Plate 
I, fig. 3,) the larger hermit-crab, Hupagurus pollicaris, (p. 313,) the 
smaller hermit-crab, H. longicarpus (p. 313,) the Heteromysis formosa, 
(p. 396,) Mysis Americana, (p. 396,) Unicola irrorata, (p. 340, Plate 1V 
fig. 19,) Amphithoé maculata, (p. 315, Plate LV. fig. 16,) Corophium cyl- 
indricum, (p. 370,) which lives among the hydroids, and a species of 
Autonoé, which lives in the crevices among the lobes of the sandy 
ascidians (Amarecium pellucidum) in large numbers. The barnacle, Bal. 
anus crenatus, (p. 396,) is very abundant. 
One of the most interesting of the Crustacea met with was the Het- 
erocrypta granulata, which occurred off Falmouth and near Suconesset 
light-ship. This is one of the triangular crabs in which the carapax is 
smooth ; the chelipeds are long and triangular. It is a southern 
species, occurring on the Florida coast, and is new to our fauna. 
Another triangular crab, the Pelia mutica, also occurs On these bot- 
toms, but this has a rough carapax, and resembles a small specimen of 
the common spider-crabs, Libinia. 
Clinging to and creeping over the hydroids and ascidians a singulai 
long-legged Pycnogonid is often met with on shelly bottoms. This is the 
Phoxichilidium mavillare, (Plate VII, fig. 35.) It is most frequently 
deep purple in color, but gray and brown specimens are often met with. 
The larvee of a fly, Chironomus halophilus, was dredged in five fathoms. 
The Annelids are quite numerous, and the majority of them are the 
same as those found on the rocky bottoms, for the same species inhabit 
the interstices of the massive ascidians, found equally on both kinds of 
