INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 381 



The destructive liabits of this species were tirst brought proiniiiently 

 to uotice, in 1811, by the celebrated liobert 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 aud 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 " gribble.'' 



The remedies used to check its ravages are chietly 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 filum. 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 anteuuiv 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 aud 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, BaJanus halanoides, 

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

 tides, aud 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 ehiiyneiis, is also common 

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

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

 stakes, bottoms of vessels, &c. It is chiefiy 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 jKire fresh water, for Professor Jeffreys Wymau has 

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

 John's Eiver, 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 moUusks. 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. croiatus, 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 tintinahulum. 



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



