[335] INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 41 
there are many animals that find congenial resorts on such flats. Then 
there will sometimes be pools or rivulets of sea-water on the sandy flats, 
in which certain creatures often spend the short time while thus impris- 
oned by the tide. 
The special localities where the sand-dwelling species of this region 
were chiefly studied, are the beaches on Naushon and adjacent islands ; 
Nobska Beach and several other beaches near Wood’s Hole; the exten- 
sive sand-beach between Falmouth and Waquoit; the beach at Menem- 
sha Bight, on Martha’s Vineyard ; several beaches on the shores of 
Buzzard’s Bay; the beaches at South End, Savin Rock, and other local- 
ities near New Haven; the beaches on Great South Bay, Long Island ; 
_ the beaches at the mouth of Great Egg Harbor, New Jersey, &c., be- 
sides the outer beaches at various other points. 
Along the upper part of the sand-beaches there is generally an almost 
continuous belt of dead sea-weeds, broken shells, fragments of crabs, 
lobsters, and various other débris cast up by the waves. Although 
many of the dead shells, &c., which occur in this way, belong really to 
the sandy shores near low-water, others have come, perhaps, from deeper 
water and other kinds of bottom. ‘Therefore, although such rubbish- 
heaps may afford good collecting grounds for those who frequent the 
shores after storms, it would be useless to enumerate the species that 
more or less frequently occur in them. Beneath such masses of decay- 
ing materials many insects and crustacea occur, together with certain 
genuine worms. Part of these are truly marine forms, and are never 
found away from the sea-shores, but many, especially of the insects, are 
in no sense marine, being found anywhere in the interior where decay- 
ing matters abound. The two-winged flies (Diptera,) of many kinds, 
are especially abundant, and their larvee occur in immense numbers in 
the decaying sea-weed. Some of these flies are, however, true marine 
species, and live in the larval state in situations where they are sub- 
merged for a considerable time by the tide. I have often dug such 
larvee from the sand near low-water mark, and have also dredged them 
at the depth of four or five fathoms off shore. During unusually high 
tides immense quantities of the fly-larvee will be carried away by the 
encroachment of the waters, and thus become food for fishes of many 
kinds, and especially for the young ones, which frequent the shallow waters 
along the shores. There are also many species of beetles (Coleoptera) 
which frequent these places, and several of them are genuine marine 
insects, living both in the larval and adult conditions in burrows be- 
tween tides. Among these are two or three species of Bledius, belong- 
ing to the Staphylinide ; several tiger-beetles (Cicindela,) and represen- 
tatives of other families. The “ tiger-beetles ” are very active, carnivo- 
rous insects and frequent the dry sands just above high-water mark; 
when disturbed they rise quickly and fly away to the distance of sey- 
eral yards before alighting. They are so wary that it is difficult to catch 
them without a net. Most of the species reflect bright, metallic, bronzy or 
