of even the hardest oak, and placed for the purpose of defending 

 the coast of the Netherlands against the sea, were eaten through, 

 in a few months ; and so weakened, as to be broken by the slightest 

 force. Surprised at this alarming phenomenon, they inquired into 

 its cause, and found that, by the astonishing increase in the number 

 of these animals, the inhabitants were threatened with the greatest 

 danger. To this alarm we owe the account given by Dr. Baster; 

 the inquiries of Dr. Massuet*; and the diffuse and elaborate, but 

 truly learned work of Sellius-f . 



That the fossil remains of wood, here depicted, have derived 

 their present appearance from the devastation of these same crea- 

 tures, there is very little reason to doubt ; since we find in them 

 most of those characteristics of the testaceous habitation of the 

 teredo, which Sellius has so accurately described. We here see the 

 external small opening, dilating as it penetrates the substance of 

 the wood the same testaceous tube, its external surface bearing 

 somewhat of an annular appearance ; whilst its internal part pre- 

 sents a finely polished surface, except where invested with lapideous 

 matter; and, in one specimen, an appearance resembling the hard 

 testaceous cutting hemispheres may be seen, left in the wood, which 

 they have been excavating, and petrified with it. In these speci- 

 mens we also discover the frequent close neighbourhood of the 

 different dwellings of these animals ; and remark, with admiration, 

 the care and wonderful contrivance by which they have guided 

 themselves, so that they should not render inconvenience to each 

 other ; reminding us, that 



parcit 



Cognatis maculis similis fera. 



Thus we rarely see an instance of their at all invading each other's 

 premises, whilst pursuing their frequently tortuous passage ; but 



* Recherches interessantes 1'Origine, &c. des diverses Especes de Vers, a Turgeau. 

 t Historia Naturalis Teredinis Marine. 



