lV INTRODUCTION. 
~ WHENatsea, I havefrequently lowered down 
my boat to take in floating wood, (wreck), sea- 
weed, &c. which often contained many inter-. 
esting vermicules and small shells. The wood 
was generally pierced by the Teredo Navalis.— 
This animal first attaches itself in the state of 
animalcvle to the bottouisof ships, if not sheath- 
ed with copper, where it increases rapidly, and 
in a short time pierces the planks, growing 
larger, and forming its shell as it penetrates. 
WHALES, tortoises, &c. have frequently bar- 
nacles of a rare description adhering to them: 
indeed the Lepas attaches itself generally to 
substances of every description. 
Tue Author having observed that the bot- 
toms of ships soon became covered with bar- 
nacles in tropical climates, made the following 
experiment while lying at Magadore, on the 
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