TEREDO. 213 



will step in to announce the truth and dispel the mists Qf 

 prejudice. 



I am, Gentlemen, your most obedient servant, 



WILLIAM CLARK. 



TEREDO, Adanson. 



I infer that this genus is still involved in great obscurity 

 from the serious mistakes that exist in the accounts of it : 

 this is the more remarkable, as it has attracted great atten- 

 tion for the last 200 years, in consequence of its devasta- 

 tions, which have been so alarming, that various governments 

 have called in the aid of the learned and scientific to examine 

 into their nature, and suggest the best means of preventing 

 them. 



Some authors, amongst them Sir Everard Home, call the 

 external veins the ducts of the testicles, and say the heart is 

 situated near the head. More modern accounts state that 

 there is no true hinge ; that the ligament is obsolete, and the 

 foot rudimentary or absent ; the branchiae are described as 

 long brown fleshy cords ; the elastic stylet is mentioned as a 

 club-shaped body peculiar to Teredo, and the animal is said to 

 be furnished with two stomachs. Some observers say, that the 

 anterior adductor muscle is well marked, but the posterior one 

 slightly ; others affirm the branchiae to be the ovaria, and that 

 the protective tube of Teredo megotara is destitute of the pos- 

 terior circular laminae. I propose to show that not one of 

 these statements is correct. I am informed that M. Deshayes 

 has given anatomical details of one or more of the Tere- 

 dines in his work on the ' Mollusques d' Algerie/ which I have 

 had no opportunity of consulting ; I must therefore abide by 

 my own views. 



The origin of this account was the receipt from Exmouth of 

 a pine stake, which had doubtless served as a water-mark in 

 one of the channels of the estuary, and being destroyed by the 

 perforations of these creatures, was taken floating in the offing 

 at that place. I received the mass enveloped in sea-weed, 

 accompanied by bottles of sea-water. The log contained fifty 



