INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 381 



The destructive habits of this species were first brought prominently 

 to notice, in 1811, by the celebrated Robert Stephenson, who found it 

 rapidly destroying - the wood -work at the Bell Eock light-house, erected 

 by him on the coast of Scotland. Since that time it has been investi- 

 gated and its ravages have been described by numerous European 

 writers. It is very destructive on the coasts of Great Britain, where it 

 is known as the ;' gobble.'' 



The remedies used to check its ravages are chiefly copper or other 

 metallic sheathing; driving broad-headed iron nails, close together, 

 into the part of the piles subject to their attacks ; and applying coal- 

 tar, creosote, or verdigris-paint, once a year or oftener. 



Another singular crustacean, common on the piles at Wood's Hole, 

 is the Tanais filwn. This is a very slender, whitish species, almost 

 thread-like in form, but has the first pair of legs much thickened, with 

 very peculiar, stout claws, ovate in form ; the rest of the anterior legs 

 are very slender. The antenna? are short and thick, the inner ones di- 

 rected forward; the outer ones more slender, and curved outward and 

 backward. This species lives among the adhering ascidians and hy- 

 droids on the piles, and has also been found in deeper water, in the Bay 

 of Fundy. Its habits are little known, but some of the allied species 

 have been accused of boring in wood. 



Two species of barnacles are very common on the piles of the 

 wharves. The common barnacle of the rocky shores, Balanus balanaides, 

 (p. 305,) is also common on the piles of wharves and bridges, between 

 tides, and also on the bottoms of vessels, &c. It never grows very 

 large, although it may become so crowded together as to form a contin- 

 uous crust. It is easily distinguished from the other species by its 

 membranous base, which never forms a solid plate, like that of the 

 other species. The " ivory-barnacle," Balanus ebumeus, is also common 

 on all kinds of submerged wood-work, whether fixed or floating. It 

 is usually abundant on the piles and timbers of wharves, buoys, oyster- 

 stakes, bottoms of vessels, &c. It is chiefly found below low- water 

 mark if on fixed objects, and 'is even more common in the brackish 

 waters of estuaries than in the purer waters outside, and it is capable 

 of living even in pure fresh water, for Professor Jeffreys Wyman has 

 sent me specimens collected, by himself, about sixty-five miles up the Saint 

 John's River, in Florida, where the water is not at all brackish. This 

 species is sometimes found adhering to the carapax of crabs, the 

 shell of Limulus, and various mollusks. It is easily distinguished from 

 most species on account of its low, broad form and its smooth white 

 exterior. It has a shelly base. The B. crenatus, common on shells and 

 stones in deep water, also occurs on vessels. Other species are often 

 found on the bottoms of vessels that have come from warmer latitudes. 

 Some of them are of large size. One of the most frequent of these is 

 Balanus tintinalnduni . 



Several species of u goose-barnacles," Lepas, are frequently found 



