OF THE MERG-UI ARCHIPELAGO. 



13 



large and ten very small, broadest at the margin and slender 

 within, the larger exsert and the smaller very incised at the free 

 inner edge, all granular at the sides. Costa? larger than the 

 septa, and rarely extending far from the calicular margin. 

 Columella small and deeply seated, composed of a few trabecular. 

 Endotheca scanty. Gemmation frequent, and from the ccenen- 

 chyma, one part of a bud being close to a calice. Eissiparous 

 calices occasional, large. 



Height of colony 45 millim., breadth 30 millim. ; breadth of 

 calices 1*5 to 2 millim. Locality, ACergui Archipelago. 



Genus Plesiastej:a, Ed. Sf H. 

 Plesiastr^ea i^e-erata. 



Plesiastraea indurata, Verrill, Proc. Essex Inst. ser. 2, v. p. 36, 1867- 

 A variety. 



Locality, King Island Bay. 



Genus Echixopora, pars, Dana. 



ECHIXOPOEA ASPERA. 



Madrepora aspera, Ellis $ Solander, Hist, of Zooph. p. 156, pi. 39, 1/86. 

 Echinopora aspera, Dana, U.S. Expl. Exped., Zooph., vol. vii. p. 281, 

 1846. 



Locality, King Island Bay. 



Genus Leptastej:a, Ed. § H. 



Leptastr^ea httmilis, sp. nov. (Plate I. figs. 23, 21.) 



The colony is low, gibbous and encrusting, covering a consi- 

 derable surface. The corallites are small and short, close, closely 

 united near the base by the fused walls, but separate slightly 

 above, so that the margins of the calices are close but not joined, 

 there not being any costse in the interval. Calices variable in 

 size and shape, rarely circular, widely open, and having a narrow 

 and deep fossa. Septa in three cycles, with orders of the fourth; 

 primaries the largest, entire above and dentated within ; secon- 

 daries decidedly less exsert than the primaries ; the septa of the 

 fourth and fifth orders small. Columella deeply seated, very 

 small. Endotheca well developed. Increase by gemmation from 

 the marginal calices of the colony. 



Height of corallites 9-10 millim., breadth of calices 2-4 

 millim. Locality, Mergui Archipelago. 



