142 A. Alcock — Newly-recorded Corals from tlie Indian Seas. [No. 2, 



The septa are hardly exsevt, and they resemble the costaa, with which 

 they are continuous, in being finely and uniformly granular. 



Pali, in the form of series of very small denticles, stand before 

 the primary and secondary septa, and also before the united margins of 

 the fcerfciari.es and quaternaries of each half-system. 



The columella is distinct and consists of contorted granules. 

 Dredged by Professor Wood-Mason in the Andaman Sea. Every 

 specimen, as in the case of H. ceqnicostatus and H. philippensis, is per- 

 forated and tunnelled in the base by a worm. 



The distinctive characters of this species are (1) the circular 

 ealicle almost or quite equal to the base in diameter, and not separated 

 from the base by any constriction whatever, (2) the equivalence in size 

 of the primary septa with the quaternaries standing immediately on 

 each side, and (3) the small size of the pali. 



Discotrochus, Edw. & Haime.. 



10. Discotrochus investigatoris, n. sp. Plate V, figs. 5. 5a. 



Coral! um discoid, thick and coarse. The almost horizontal base 

 culminates in a coarse scar from which very distinct coarsely granular 

 costse radiate, the costae being equally distinct throughout their course 

 and all of uniform size 



The calice is very shallow. 



The septa, which are in four cycles, are slightly exsert, with thick 

 coarsely spinate or dentate edges : those of the first cycle are the most 

 prominent, and those of the third cycle the least so, but the difference 

 in si/.e between any of the cycles is not very marked. 



Tin- columella consists of a few papillae. 



Diameter of disk 8 mm., greatest thickness 2 mm. 



The single specimen was dredged by the 'Investigator' off the 

 Arrakan Coast, and appears to be a denuded fossil. 



lis possible fossil character is supported by the fact that, as Pro- 

 fessor Wood-Mason informed me, fossil Crustacea were dredged either at 

 or very near the same place during the same surveying season. The 

 exact spot at which the coral was dredged was off the Islands of Ramree 

 and Cheduba. 



In i*elation to the possible fossil nature of this species I may refer 

 to two papers in the Records of the Geological Survey of India, vol. ix. 

 (" On the Mud Volcanoes of Ramri and Cheduba " by F. R. Mallet, 

 F. Gr. S., p. 188, and '■' On the Mineral Resources of Ramri, Cheduba, 

 and the adjacent Islands," by the same author, p. 207), to which my 

 attention has been very kindly directed by Mr. T. H. Holland of the 

 Geological Survey. 



