ITS RAVAGES. 303 



he proceeds, with a shelly coat secreted by his mantle, 

 but without any attachment to his person. It is merely 

 a sort of plaster to the walls of his singular house. He 

 himself dwells at the far end of the chamber, enclosed 

 in a bivalve shell resembling that of a Pholas. The 

 long worm-like body which fills the burrow is merely 

 the extension of the siphonal tubes, which in this genus 

 are of great length. The organization of the body is 

 not very unlike that of other CONCHIPEEA,* and fluid 

 enters and is expelled through the siphons in a similar 

 way. By the older writers the Teredo was placed 

 among the Annelides, near Serpula; but this false po- 

 sition was corrected as soon as the nature of the animal 

 was understood: in modern works we find it associ- 

 ated with Pholas, to which its organization and habits 

 closely ally it. Its ravages have caused it to be ob- 

 served from very early times, and many large books 

 have been devoted to its history. Formerly, before 

 the practice of coppering ships became general, many a 

 stately vessel fell a sacrifice to its prowess ; and about 

 the middle of the last century fears were entertained for 

 the safety of Holland, the Teredo having attacked the 

 piles on which that singular country rests. Thus 

 navies can with difficulty resist the attacks of a little 

 creature apparently so unimportant; and a country 

 that braved the power of Spain in her days of strength, 

 was well-nigh sinking under the gnawing of a worm. 

 On our own coast similar destruction is going on in 

 many places. No less than six species are included in 

 the British list of Teredines; but the most undoubted 

 * See p. 66. 



