164 MADREPORARIA. 
The calicles are about 1 mm. in diameter, distinctly but slightly pitted, mostly quite 
circular. The walls are reticular and of varying thicknesses up to 0°5 mm. The reticulum is 
apparently coarse and irregular, and built of large, frosted granules. Round meshes can often 
be made out, and these are sometimes arranged in rows as if the reticulum were regular. 
Here and there on one side only of a median wall ridge an inner synapticular wall may 
appear. In the uppermost calicles the septa, projecting only far down, are short, very thick and 
frosted, with clear separation of wall and septal granules. It is only in the shallower lateral 
calicles where the large pali and the other granules form concentric series of rings. These pali, 
usually the five principals, rise high as thick, stout, frosted rods. The fossa is shallow and soon 
filled up. The central tubercle is very small. The interseptal loculi are very narrow and 
inconspicuous between the thick, frosted septa. 
The large frosted granules of the walls give a soft woolly appearance to the coral. The 
section appears to be trabecular and dense. There are traces of a light yellowish fawn colour. 
There was no special reason why this coral should have been called P. lutea (see p. 34). 
There is only one specimen, which seems to have been affected by a boring sponge, and, when 
collected, half of the upper surface had been killed. The reticulum, consisting of coarse 
granules, is its most interesting feature. 
a. Zool. Dept. 86. 12. 9. 319. 
161. Porites Philippines @)4. (P. Philippina quarta.) 
[Mactan Islands, coll. H.M.S. ‘ Challenger’; British Museum. ] 
Syn. Porites mirabilis Quelch, Chall. Rep. xvi. (1886) p. 185, pl. xi. figs. 5, 5a. 
Description.—The corallum is massive, coarse, and gibbous, encrusting at the base. 
The calicles are sub-polygonal, from 1-1:15 mm. in diameter, nearly superficial, but 
slightly excavate. The walls are rather narrow, acute, often thickened, and very porous ; the 
septa are very thin; there are five to six long pali, and a styliform columella. 
The texture is close and firm, very finely reticulated. 
This specimen, the original of which has been mislaid, and was not available for examina- 
tion by the author, was distinguished by an immense number of double calicles, and these 
presented so remarkable an appearance that Mr. Quelch thought them a reliable specific 
character. They can be found on most specimens, and their presence in great numbers in this 
particular specimen was probably accidental. 
The above description is from Mr. Quelch’s text. 
