276 THE OCEAN. 
calls himself lord and proprietor of this new crea- 
tion.””* 
The species of Polypes which contribute to the 
formation of coral structures are very numerous, 
and differ greatly from each other in the forms of 
their respective habitations. Some form large round- 
ed masses, with numerous winding depressions, ag 
the Brainstones (Meandrina); some are studded with 
holes, filled with thin shelly plates placed perpen- 
dicularly, and converging to a point in the centre, 
as Astrea; some assume the appearance of a mush- 
room, as Agaricia; but the most general form is 
that of an irregular, branching shrub. The various 
kinds are not found scattered indiscriminately over 
the whole edifice, but each occupying its own zone 
and position, each performing its own part, assigned 
by God, in carrying up the wondrous architecture. 
The principal and most important place is filled by 
the genus Porites, which occupies the outside of the 
reef, at the exposed edge, constructing large rounded 
masses. The next in importance is the Millepora 
complanata, which forms thick vertical plates, unit- 
ing at different angles by their edges, so as to pre- 
sent the appearance of a honeycomb: the marginal 
plates only being alive. These two kinds alone 
are able to endure the intermitting exposure to 
which the upper edge is subject, in being conti- 
nually washed over by the surf; other species are 
found a few fathoms down. Inside the lagoon, 
there are quite distinct sorts, generally brittle, and 
thinly branched; while great round Brainstones 
* Kotzebue’s Voyage, 
