No. 35. TEREDO. 

 Ship Worm. Inhabitant a Terebella or Ascidia. 



The Teredo is furnished with two calcareous, hemispherical valves or 

 maxillae, truncated before, and two others of a lanceolate form; shell tapering, 

 flexious, and penetrating wood. It is described and figured in Vol. 61, of 

 the Philosophical Transactions, (see Doner British shells.) Only four species 

 of this singular genus have yet been discovered," which are termed Navalis, 

 Aticulus, Clara and Xytoc, carpum granatum. Two ok these species of 

 Teredo are found in holes which they perforate in wood; a third, in the seed 

 vessels of a plant which grows in the East Indies, and called by Linnaeus 

 Xytoc, carpum granatum; and the fourth, the Gigantic Teredo, in mud, at 

 the bottom of the ocean. On the coast, in the island of Battoo, near Sumatra, 

 the shells of these are five or six feet in length. 



Great numbers of the ship worm, which are supposed to have been intro- 

 duced from India into Europe, are sometimes found in the sides and bottoms 

 of ships; so much so as even to endanger their sinking. By means of their 

 hard and cutting jaws, they are able to penetrate into any timber, except such 

 as is of an extremely firm and compact substance. They, Jiowever, bore as 

 seldom as possible across the grain; for, after they have penetrated a little 

 way, they turn, and continue with the grain, tolerably straight, until they meet 

 with another shell, or a knot: their course then depends on the nature of their 

 obstruction; if considerable, they prefer making a short turn back, in the form 

 of a syphon, rather than to continue any distance across. Colonel Montague 

 states that he had an opportunity of examining a great number of their shells, 

 in the dock-yard at Plymouth, G. B., where every possible means have been 

 tried, to prevent the ravages which are committed by them. Piles which 

 have not been in the water more than four or five years, though of solid oak, 

 were found, on examination, to be greatly perforated by them. In the year 

 1730, the inhabitants of Holland were under serious alarm concerning these 

 worms, which had made dreadful depredations in the piles that support the 

 banks of many parts of those coasts. One of the parties who had the care of 

 the coasts at the time, observed, to his astonishment, that some of the timbers 



