INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 335 



tliere are maDy 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 onNaushon 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 Eock, and other local- 

 ities near New Haven ; the beaches on Great South Bay, Long Island ; 

 the beaches at the mouth of Great Egg Harbor, Xew 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 debris 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, esi)ecially of the insects, are 

 in no sense marine, being found anywhere in the interior where decay- 

 ing matters abound. The two-winged flies (DqHera,) of many kinds, 

 are especially abundant, and their larvie 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 

 larvae 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-larvfe will be carried away by the 

 encroachment of the waters, and thus become food for fishes of many 

 kinds, and especially for the youngones, which frequent the shallow waters 

 along the shores. There are also many species of beetles (Co?eo2?^em) 

 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,helong- 

 ing to the StaphyUnidw ; several tiger-beetles {Ciciridela,) and represen- 

 tatives of other families. The '' tiger-beetles " are very active, carnivo- 

 rous insects and frequent the dry sands just above high-watermark; 

 when disturbed they rise quickly and fly away to the distance of sev- 

 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 



