1893.] A, Alcock — Newly-recorded Corals from the Indian Seas. 149 



Bathyactis, Moseley. 



26. Bathyactis stephanus, n. sp. PL V, figs. 12, 12a. 



Corallurn very thin and fragile, circular, strongly convex, the base 

 forming an inverted bowl. The costee radiate from the centre and 

 gradually become laminar or crested as they approach the margin : the 

 primaries are the most distinct. 



Septa in six regular systems and five complete cycles arranged 

 exactly as in Bathyactis symmetrica. Those of the first three cycles are 

 foliaceoas, with crenulated surfaces and irregularly lobate edges. 



Synapticulse distinct in ten to twelve zones, which though fairly 

 regularly concentric do not at once attract the eye by this character as 

 they do in Bathyactis symmetrica. Columella distinct, umbilicated. 



Diameter of corallum 34 mm., its greatest height from margin of 

 base to the tips of the tallest foliaceous primary septa 17 mm. 



The colour of the soft parts is a ruddy mauve. 



Four specimens from the Bay of Bengal off the Kistna Delta in 

 678 fathoms. 



EXPLANATION OF THE PLATE. 



Figs. 1, la, Paracyathtts cavatus, natural size ; 



Figs. 2, 2a, Pa?-acyathus fulvus, natural size ; 



Figs. 3, 3a, Paracyathus porphyreus, natural size ; 



Figs. 4, 4a, Heteroci/athios wood-rnasoni, natural size ; 



Figs. 5, 5a, Discotrochus investigatoris, enlarged five times ; 



Figs. 6, 6a, Polycyathus andamanensis, natural size ; 



Figs. 7, 7a, Balanophyllia scabra, natural size ; 



Figs. 8, 8a, Eupsammia regalis, natural size ; 



Fig. 9, Heteropsammia aphrodes, natural size ; and 9a, viewed from 



above, enlarged twice ; 

 Fig. 10, Cycloseris mycoides, natural size ; 

 Fig. 11, Diaseris fragilis, natural size ; 

 Figs. 12, 12a, Bathyactis stephanus, natural size. 



