350 Mr. P. H. Gosse on a new living British Madrepore. 



in P. americana the summits of the primary septa are described 

 as arched, in our Weymouth specimen that character exists 

 only in some of them, others, of the same cycle, being obliquely 

 truncate, the outer part being the higher. 



These differences are too slight to constitute distinction of 

 species; and hence I conclude that we have on our southern 

 coasts a Phyllangia now living, in some abundance, which has 

 hitherto been recognized only as inhabiting the Caribbean Sea. 



I was not so fortunate as to see the animal alive, my specimen, 

 though in the flesh, being in an advanced state of decomposition 

 when I obtained it ; but Mr. King, who is familiar with Cyathina 

 Smithii, speaks of the living Phyllangia as having a general 

 resemblance to that species, and tells me that he observed white 

 and green hues. He noticed numerous tentacles, but did not 

 observe whether they were knobbed. 



It may be fairly expected that more specimens will be obtained 

 of this interesting little Coral ; and to facilitate the search for 

 it, I may mention that this colony was taken just under White- 

 nose. 



The following diagnosis may assist in its recognition : — 



MADREPORARIA. 



Tegumentary structure solidified so as to form a proper corallum. 



APORA. 



Visceral chamber free, or subdivided transversely by irregular 

 projections. Septa well developed. Sclerenchyma compact. 



Astraeidae. 



Intersepts more or less divided transversely by projecting 

 plates. Visceral cavity not obliterated, but only subdivided. 

 No ccenenchyma. Walls imperforate. 



ASTILEINA. 

 Septa toothed. 



Astrangiace^e. 



Increasing by buds, which spring from stolons, or from creep- 

 ing basal expansions. Polypary always remaining very short. 



Phyllangia. 



Wall naked, ribbed. No false ccenenchyma. Primary septa 

 with the upper edge untoothed. Columella rudimentary. 



P. americana. Four cycles of septa. Primary septa with the 

 outline of their summits arched. 



