IV. AND REVIVED. 123 
them difficult to be found ; and one mutt be ac- 
cuftomed to obfervation, and have an acute eye, 
before he is able to fee them. A {mall longitudi- 
nal fafcia, covered with fpecks, is ob{curely feen 
in the middle: and above it a circle, more vifi- 
ble, formed as it were by two C’s touching at 
the extremities. The origin of a little canal is 
feen at the upper part of the circle, A. B. fig. 3. 
The animal being very flexile, it aflumes fome 
extraordinary fhapes in its progreflion. Some- 
times extending, it becomes very flender, then it 
contracts into extreme corpulency. Sometimes 
the anterior part is contracted and concealed in 
the body, or the fame happens to the pofterior 
part. Some of the body will be inflated, while 
the reft is flaccid, or it will exhibit other motions 
as eafy and fingular to behold as they are difficult 
to defcribe with precifion ; and all thefe remark- 
able figures fucceflively follow, though the ani- 
mal remains {tationary. 
~The wheel animal ufes the following method 
_ to tranfport itfelf from one place to another. It 
fixes the extremity of the tail to the plane which 
it intends to traverfe : then it extends the whole 
anterior part of the body. While in this ftate, 
the animal detaches the tail, and, by contraéting 
the pofterior part toward the anterior, it advan- 
ces. The extremity of the tail is again fixed to 
the plane: the body is extended as before, the 
tail 
