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XIII. Observations on the Shell of the Sea Worm found on the 
Coast of Sumatra , proving it to belong to a Species of Teredo ; 
with an Account of the Anatomy of the Teredo Navalis. By 
Everard Home, Esq. F. R. S. 
Read May i, 1806. 
The shell of the sea worm from Sumatra, had only to be 
seen by any one engaged in comparative anatomy, to arrest 
his attention, and excite a desire for further information 
respecting it. 
In the spring 1805, Captain Maxwell of the Calcutta East 
Indiaman, obligingly gave me a specimen of this shell, five 
feet long, but imperfect at both extremities. He said it was 
brought from Sumatra, but could give me no further account 
of it. The appearance externally, and its radiated structure, 
led many of my friends to consider it as a mineral substance, 
formed into a hollow stalactite. Sir Joseph Banks, however, 
decided on its being the shell of a sea worm. The only means 
of ascertaining this point then in our power was adopted. It 
was analysed by Mr. Hatchett, who found that it was com- 
posed of carbonate of lime, and an animal gelatinous substance, 
which is greater in quantity than in the chama gigas, but less 
than in the common oyster. 
Having determined that it was a shell, I applied to Mr. 
Marsden, as the person best acquainted with the natural 
