VII.—REPORT UPON THE INVERTEBRATE ANIMALS 
OF VINEYARD SOUND AND THE ADJACENT 
WATERS, WITH AN ACCOUNT OF THE PHYSICAL 
CHARACTERS OF THE REGION. 
By A. E. VERRILL. 
A._UABITS AND DISTRIBUTION OF THE INVERTEBRATE 
ANIMALS. 
I.—GENERAL REMARKS. 
The investigation of the invertebrate life of these waters, undertaken 
at the request of the United States Commissioner of Fish and Fisher- 
ies, was actively carried forward during the entire summer of 1871, 
and the very extensive collections then made have been studied by Mr. 
8. I. Smith, Mr. O. Harger, and myself, as thoroughly as possible dur- 
ing the time that has been at our disposal. The work upon the collec- 
tions is by no means complete, but is sufficiently advanced to serve the 
immediate purposes of the Fish Commission. 
To Mr. Smith I am indebted for the identification of all the Crustacea 
referred to in this report and the accompanying lists, except the Iso- 
pods, which have been determined mostly by Mr. Harger, to whom my 
thanks are also due for several excellent drawings of those animals. 
To Professor A. Hyatt Iam indebted for the identification of some of the 
Bryozoa, and for most of the figures of.that class. I am also under 
obligations to Dr. A. 8S. Packard, Dr. G. H. Horn, and Dr. H. A. Ha- 
gen, who have identified the insects inhabiting salt water. 
According to the plans adopted these explorations had in view sev- 
eral distinct purposes, all more or less connected with the investigation 
of the fisheries. The special subjects attended to by this section of the 
Fish Commission party were chiefly the following : 
1st. The exploration of the shores and shallow water for the purpose 
of making collections of all the marine animals and alg living between 
tides, on every different kind of shore, including the numerous burrowing- 
worms and crustacea, and to ascertain as much as possible concerning 
their habits, relative abundance, stations, &c. 
2d. The extension of similar observations by means of the dredge, 
trawl, tangles, and other instruments, into all depths down to the deep. 
est waters which were accessible to us, and to make a systematic sur- 
vey, as complete as possible, of all the smaller bays and harbors within 
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