[ r 73 3 
cdve about its Edges a very lively Motion } and when 
the ‘Polypus prefents itfelf in a certain manner, it 
difcovers, on either Side of thefe Edges of its ante- 
rior Part, fome what very much refembling the Wheels 
of a little Mill, that move with great Velocity. 
Thefe Polypi are able to contract themfelves j and 
they do fo often, and fuddenly. They may be 
brought to contrad at any time, either by touch- 
ing them, or by moving the Body to which they are 
fixed. When they contrad, the Edges of their an- 
terior Parts are drawn quite into their Bodies 5 and 
when they refume, which they do foon after, their 
former Pofture, one may diftindly fee thofe Edges 
come forth again, and put themfelves in Motion, as 
before. 
When one looks about the anterior Parts of thefe 
Polypi , which are open, and whofe Edges are in 
Motion, one may frequently have an Opportunity 
of remarking a Number of very minute Bodies 
fwimming in the Water, that feem to be forced 
down with Velocity into thefe Openings of their 
anterior Parts, and that fometimes are thrown out 
' again from thence. 
To make this Obfervation the moft fenfible, it is 
beft not to look at a fingle Polypus , but a Clufter 
of fome Numbers of them together. 
1 have taken (notice, that the Polypi of the Sort 
in Queftion, appear of a brownifh Colour when 
viewed with the Microfcope $ I fhould now add, that 
having left fome of them for feveral Days in the 
fame Water, they by degrees loft their brown Co- 
lour, and became tranfparent ; excepting only that a 
few Grains or Spots of Brown or Black, ftili conti- 
tinued 
