C 35 3 
fame manner with thofe of the turbinated kind t 
and it is common for all turbinated fhell-fifh, as 
they increafe in bulk, and enlarge their fhells, 
to leave their bottom or firft formed convoluti¬ 
ons. Therefore I make no doubt but the fame 
is done by the concamerated tribe; for if the 
gut go through only one or two valves, it will 
be a fufficient ftay to the animal, -and being 
contraQ;ed or dilated, will ferve all t he purpofes 
'above mentioned. How far this is pra8;icable by 
our little inhabitant, cannot abfolutely be deter¬ 
mined ; but if it be conftantly fixed by the gut 
to the fiphunculus, it has a furprifing power of 
contraBing and dilating its body, to expend fo far 
as the bottom or point of the Bdemnite, which is 
more than thirty times the length of the cell, 
into which it returns. I am apt to think, this 
gut or duBus, as well as the body of the crea¬ 
ture, is capable of being extended very confi¬ 
de rably, to ferve all the ufes of forming the 
Bdemnite, without leaving the fiphunculus; and 
that the gut ferves for the fame purpofes with ^ 
the tendons of the oyfier; the latter to open 
and fhut the fliell; the former to allow the ani¬ 
mal to go out and in at pleafure. And as the 
oyfter feeds altogether in the fhell, by opening 
the verge, the Bdemnite (whofe refidence is 
in the great deep, which is feldom diflurbed) 
very 
