ie CORALS AND CORAL ISLANDS. 
repora cribripora D., a species collected in the Feejees, is rep. 
resented much enlarged in the accompanying figure. The nat- 




POLYP OF M. CRIBRIPORA, D. 
ural size of the expanded polyp in this genus is generally 
from an eighth to a twelfth of an inch across the star. The 
disk of the polyp is quite small, and the number of tentacles is 
always twelve. The most common color of the polyps is green, 
while that of the general surface between is ordinarily a pale 
or a dark umber. In many species of Madrepora the branch- 
es spread out laterally from a central or lateral trunk, and co- 
alesce together into a complete net-work, having the form of a 
shallow vase; and the interior of the vase is filled with multi- 
tudes of short, cylindrical coral stems, rising from the reticula- 
ting branches, which, when alive, have literally the aspect of 
sprigs of flowers in the vase. 
In certain kinds, closely related to Madreporie, the calicles 
are reduced to points, or spiniform or angular prominences, or 
fail altogether, and there are sometimes rounded promi- 
nences between the cells; these degraded Madrepores belong 
to the genus Montipora (Manopora of the Author’s Report). 
The genus Dendrophyllia is also referred to the Madre- 
pore tribe. The budding, as already explained, is of the 
same kind as in the Madrepores. But the tentacles exceed 
twelve. One of the polyps of D. nigrescens D., enlarged, is 
shown in the figure, on page 75. This Pacific species grows to 
a height of at least three feet, and is peculiar in having a very 


