14 THE OCEAN. 
‘tioned, is a distinct and independent animal; but 
there are some which, while they possess a general 
similarity in structure to these, exist only in aggre- 
gated communities; many individual Polypes being 
clustered upon a somewhat solid body called a Po- 
lypidom, which is, when alive, clothed with a fleshy 
coat, believed to be capable of communicating and 
receiving sensations to or from all the Polypes. 
The teat-shaped bodies, familiarly called by the 
fishermen Cow’s-paps, when simple, and Dead-man’s 
toes, when branched, is a common example; the 
Alcyonium digitatum of zoologists. It consists of 
a leathery substance, capable of contraction, studded 
with orifices, whence project little stars with eight 
rays, which are the expanded tentacles of the small 
Polypes that inhabit the hollows. Those beautiful 
productions, the Corals, some of which I may have 
occasion to notice hereafter, are also formed on the 
same model. They have generally a more solid 
stem, partaking of the nature of stone, and branch 
out in imitation of shrubs. The stony or horny 
centre is, however, clothed with gelatinous flesh, in 
which, as in the former instance, hollows occur at 
intervals, occupied by minute star-shaped Polypes. 
The warty white coral (G@orgonia verrucosa), not 
uncommon with us, is of this structure, having a 
stony skeleton; but in the beautiful Sea-fan (@. 
fiabellum), the skeleton shows more the texture of 
bone, or perhaps of -horn; it is black, but is clothed 
with flesh of a yellow colour, or sometimes purple. 
From the ramifications being very numerous, and 
uniting with each other at short intervals, like the 
