ME. H". M. BEEXARD ON EECENT POEITIDiE. 149 



led to a review of the present situatioB, in wliicli tlie funda- 

 mental theory on which the existing system of classification 

 which we owe to Milne-Edwards and Haime rests was criticised in 

 the light of recent research. This criticism entailed a re-state- 

 ment, with slight amplification, of the author's phylogenetic 

 scheme, along the lines of which it is maintained the classifica- 

 tion of the Stony Corals will have, for the future, to proceed, 

 i. e. until it is again superseded by further advances in morpho- 

 logical science. The chief new points of interest with regard 

 to this scheme related, (1) to the origin of septa ; (2) to the 

 various possible methods in which the primitive external epi- 

 thecal cup may have been flattened and become rej)laced by an 

 internal skeleton. 



This last discussion brought us naturally to the object of the 

 paper, viz., to enquire along what lines of development Porites 

 obtained its peculiar internal and so-called "trabecular" skeleton. 



The conclusions arrived at were : — 



(1) The " trabecular " septum is only a misleading name for 

 perforated lamellate septum. 



(2) The Poritid skeleton can be explained as an immature 

 Madreporid skeleton, arrested in its growth by very early 

 budding. 



(3) As this may have happened more than once, Porites may 

 be polyphyletic in origin. 



The paper concludes with a brief discussion of the various 

 genera which have been from time to time united with Forites ia 

 the same family or else separated from it as generically distinct. 

 The revision suggested leaves the family Poritidse as Dana left it, 

 with only two genera, Porites and Qoniopora, — Porites enlarged 

 by the absorption of Synarcea, Napopora, Neoporites, and Cosmo- 

 porites, and Goniopora also enlarged by the merging with it of 

 Phodaroea and Ticlwpora. 



My best thanks are due to my friend Prof. F. Jeffrey Bell for 

 much kindly assistance, and for the warm interest he has 

 taken in these investigations, not only as the Officer in charge 

 of the Collections on the study of which they are based, but also 

 in the interest of zoological science. 



