12 



PKOF. P. M. DUNCAN ON THE MADREPORARTA 



colony, Pissiparous division occurs, and it is evident that it 

 is the usual method of increase, but gemmation from the basal 

 epitheca seems to happen. Columella deeply seated and very 

 small. 



Length of the colony 24 centira., breadth 14 ; height of the 

 encrusting mass less than 10 millim. Diameter of calices from 

 3 millim. with forty septa, 5 millim. of the same septal number, 

 8 millim. with fifty-six septa. Locality, Mergui Archipelago. 



Genus Heliastr^a, Ed. Sf H. 

 Subgenus Ulastr^a, Ed. Sf H. 

 Heliastr^a (Ulastr^a) crispata. 



Astrsea crispata, Lamk. Hist. Anim. s. Vert. t. ii. p. 265, 1816; 2 edit, 

 p. 416. 



Ulastrsea crispata, Ed. &f H. Ann. des Sc. Nat. 3 ser. t. x. pi. 9. fig. 4, et 

 t. xii. p. 116, 1850. 



Locality, Mergui Archipelago. 



Genus Phymastr^a, Ed. Sf H. 

 Phtmastr^ia irregularis. 



Phymastrsca irregularis, Dune. Proc. Zool. Soc. 1883, p. 406. 

 Locality, King Island Bay. 



PnTMASTRiEA ASPERA. 



Phymastraca aspera, Quelch, Report on 'Challenger* Reef-building 

 Corals, p. 105. 



Locality, King Island Bay. 



Genus Solenastrje a , Ed. <$f H., 

 Amended, Dune. Rev. Farn. Sf Gen. p. 107. 



Subgenus Quelcitta. Solenastrseans sometimes increasing 



by fissiparity. 



Solknastrjea (Quelcitia) SPONGIFORM is, sp. nov. (Plate L 

 figs. 21, 22.) 



The colony in tuberose, taller than broad, more or less sub- 

 cylindrical, rounded above and narrower at the attached base. 

 Caliccs numerous, circular, and slightly raised at the margin, 

 separated by varying amounts of cellular ccenenchvma, which is 

 minutely and sharply spinulose, the spinules being short, slender, 

 jagged, and witli from one to four thorny endings. Calicular 

 fosna deep and narrow. The septa are twenty in number, ten 



