Madreporarian Subfamily Montiporine. 127 
them with the entirely different trabeculae of Porites, and 
accordingly placed Montipora among the Poritide. So far 
as my own observation goes, the two are morphologically 
distinct ; the trabecule in Porites are primitive structures, 
rising straight up from the epitheca, while in Montipora they 
are, as we have seen, quite secondary. 
Turning from the ccenenchyma to the polyps, polyp- 
cavities, method of budding, and to the forms of the corallum, 
points which are, as a rule, of prime importance, we find that 
the special development of the ccenenchyma has, as it were, 
overshadowed them. With regard to the last-named, we 
find all the typical methods of growth in each of the four chief 
divisions based upon the specializations of the coenenchyma. 
The polyps themselves are minute and their tentacles are 
little more than papille or crenulations of the edge of the oral 
disk. The polyp-cavities are also very small and the septal 
apparatus as a rule degenerated into mere vertical rows of 
projecting spines. The largest or directive septum with a 
few of the larger primaries may be more or less interruptedly 
laminate. I look upon these as survivals of a primitive lam1- 
nate condition of the septa and coste in the thick porous walls. 
The cause of this degeneration of polyps and septal apparatus 
may perhaps be correlated with the great development of 
the coenenchyma, the production of which must be a strain on 
the resources of the living organism, leading to the fixation of 
the polyp at a very undeveloped stage. In contradistinction 
to this extreme we may cite in support of our suggestion the 
cases of the Alcyonaria and Actinia, in which the polyps 
reach a very high level of development, while the skeletal 
matter deposited is either scanty or altogether absent. 
The character of the budding, as also a few further points 
on the degeneration of the septal apparatus, will be reterred 
to in the concluding section on the interrelationships of the 
Madreporide. In that connexion such matters can be more 
advantageously discussed comparatively. We shall there also 
summarize the description of the genus above given, and in 
that way emphasize the arguments in favour of classing 
Montipora with the Madreporide. 
The Genus Anacropora. 
This genus, founded by Ridley in 1884 (/. c.) to contain a 
branched coral from Keeling Island, was said to be distin- 
guished from Madrepora by the method of budding and from 
Montipora by its protuberant calicles. 
The method of budding in Madrepora, in which smaller 
