71 
In by far the larger part of these Corals the cells 
are placed side by side, united together by a larger or 
smaller quantity of calcareous cement into a rounded 
mass, a broad foliaceous expansion, or a branched sub- 
cylindrical coral. The animals of these corals cover 
them with a soft, gelatinous, very contractile coat, 
on the surface of which are studded the groups of 
tentacula, while the body is included in the lamellar 
cells. 
The cells of some of those corals which affect the 
form of masses, are compressed and contorted in no 
distinct order, and are separated from each other by 
regular ridges, as in the Brain Stone ( Meandrina ). 
In some allied species the cells are small, and the in¬ 
termediate spaces, instead of being long ridges, form co¬ 
nical eminences ( Monticularia ). 
In some ( Agaricia , Pavonaria , and Polyphyllia ), 
which form foliaceous expansions, the upper, and rarely 
the lower surface of the frond is covered with roundish 
cells, the laminas of which are extended over their sides, 
so as to unite the stars one with the other. 
The remainder consist of the corals with aggregate 
stars, and are distinguished by each of the stars being 
distinctly circumscribed. 
The cells of many of these are only longitudinally 
striated on their inner surface, and are generally united 
into a cylindrical, arborescent coral. Some of these, 
as the Madrepores ( Madrepora ), have the cells pro¬ 
minent and closely spread over the whole surface; in 
others ( Porites , Astreopora , and Alveopora), the cen¬ 
tres of the cells, instead of being lamellar, are filled with 
close-set tubercles, and the interstices between the cells 
are porous. In the Deer’s-horn coral ( Palmipora ) the 
cells are very minute, shallow, and scarcely striated on 
the sides. In others ( Poecillopora and Heliopora) they 
are larger, with raised dentated edges, but shallow, and 
sunk into a very hard solid coral: from these last the 
Seriatoporae ( Seriatopora ) only differ by the pores being 
placed in longitudinal lines. The Distichoporae ( Dis - 
tichopora) 
ROOM XI. 
Nat. Hist. 
