OF THE MERGUI ARCHIPELAGO. 



19 



granular, numerous, equal, distinct down to the ccenenchyma. 

 Intercostal spaces large and highly perforate. Ccenenchyma 

 finely spinulose and more or less perforated. There is an epitheca 

 at the edge of the base of the coral, and it is dense. 



Height of corallites above the ccenenchyma 2-4 millim. ; breadth 

 of the calices 5-7 millim. Gemmation occurs from the corallite- 

 walls. Locality, Mergui Archipelago. 



In some calices of Ccenopsammia affinis the third cycle is 

 complete and its septa are long and reach the columella in most 

 half-systems ; but occasionally there is an attempt as it were- 

 to bend towards the secondary, and there may be the rudiments 

 of a fourth cycle. In another calice as large as the last the 

 primaries are the only well-developed septa ; and in some systems 

 the secondaries are small, bent, and cribriform, and unite with 

 the columella low down, and then there are just vestiges of 

 rudimentary tertiaries. The columella in this calice is not one 

 quarter the size of that of the other. 



G-enus Astropsammia, Verrill. 



A STROPS AMMIA PEDERSOItt. 



Astropsammia Pedersonii, Verrill, Proc. Boston Soc. of Nat. Hist. 

 vol. xii. p. 392, 1869. 



Locality, Mergui Archipelago. 



Family Madreporid^; (pars), Ed. 8f H. 

 Genus Madrepora, Linn. 

 Madrepora gracilis. 



Madrepora gracilis, Ed. 8f H. HisK Nat. des Corall. iii. p. 147, 1860. 

 Locality, Sullivan Island. 



Madrepora valid a. 



Madrepora valida, Dana, op. cit. p. 461. 



Locality, Elphinstone Island. 



Madrepora surcllosa. 



Madrepora surculosa, Dana, op. cit. p. 445, pi. 32. fig. 4. 

 Locality, Owen Island. 



Madrepora hebes. 



Madrepora hebes, Dana, op. cit. p. 468, pL 35. fig. 5. 

 Locality, Sullivan Island. 



