[ 40.7 1 
As for that marine Body the Alveolus , I cannot 
think otherwife than that it is of the Nautilus Kind ; 
and which, at the Concretion or Formation of the 
BelemniteSy became accidentally lodged in its Cavity, 
in the fame Manner as all other marine Bodies be- 
came lodged in the various foffil Subftances we now 
find them in. 
I beg, Sir, to remark, that the fearching into the 
Origin of this Body is not merely curious, but of 
great Ufe* fince, if its Origin is fully afferted, we 
are then better capacitated to fearch into the Pro- 
perties and Ufes of this Stone, which I do not doubt 
are many, and which we could never have attain'd 
to, without firft having examined this principal Part 
of its Hiftory. I am. 
London , Dec. 27, 
1746. 
SIR, 
Tour mojl obedient , 
humble Servant , 
Emanuel Mendez Da Cofta s 
<TSS 
XII. 
