ORDER POLYPI CARNOSI. 493 
In the CUBOIDES, it is the emboxed one which is small 
and bell-formed. ‘The other is much larger and square. 
In NAVICULA, the emboxed one is bell-formed ; the other 
is equally large, but shaped like a shoe. 
There are also several other combinations. 
FOURTH CLASS OF THE ZOOPHYTES. 
THE POLYPI 
HAVE been thus named, because the tentacula which sur- 
round their mouth give them some slight resemblance to the 
octopus, which the ancients called polypus. The form and 
number of these tentacula vary. The body is always cylindri- 
cal, or conical, often without any other viscera than its cavity, 
often also with a visible stomach, to which adhere intestines, 
or rather vessels, hollowed in the substance of the body, like 
those of the medusz. In this case ovaries are also visible. 
The majority of these animals are susceptible of forming com- 
posite beings, by sprouting forth new individuals, like buds, 
nevertheless, they also propagate by eggs. 
THE FIRST ORDER OF POLYPI. 
POLYPI CARNOSI. (Vulgo. FIXED SEA NETTLES.) 
CoMPREHEND some fleshy animals, which have the habit 
of fixing themselves by their base, but several of which can 
