POLYNESIAN PORITES. AT 
The calicles are large, up to 1°75 mm., on the tops of the mounds, with minute inter- 
vening buds; they diminish to 0°5 in the bottoms of the valleys. The wall is a thick, rather 
coarse reticulum, with rounded pores; a median ridge with irregular granulated edges and sides, 
and with round pores, is well developed on the mounds; at the edges of the stock it is a smooth 
straggling thread running along the middle of the wall; when the ridge with part of the surface 
is worn off, the wall appears solid but for the canals or pores which penetrate it. Just below 
the edge of the ridges are irregular wall-granules, roughly corresponding with the septa. These 
latter are symmetrically arranged; they are frosted or granulated, the most conspicuous 
variation being a large symmetrical ring of twelve septal granules, inside which in the deeper 
calicles on the mounds the septa seem to slope away, so that their pali are only represented by 
one or two minute points; but wherever the calicles are shallower the pali rise up and form a 
symmetrical ring in the formula Diagram B (fig. 3, p. 19); both pali and wall granules are very 
minute and frosted. The columellar tangle is large, and its reticulum is so close and flaky as 
to appear dense at the bottom of the deep open fossa in the large calicles, but at the edges of 
the stock it comes nearer the surface, and the flattened central tubercle can be easily seen. 
The interseptal loculi form a conspicuous ring of holes in the nearly solid corallum when the 
surface is abrased. The fact that the skeletal elements all round the edges of the tableland 
are thinner, and the reticulum more flaky and open, that is, has much larger pores, shows con- 
clusively that the stock grows out laterally round the edges. 
The single specimen of this coral is a portion of a flat cake with projecting edges, such 
as is shown in the diagram, Pl. XIII. fig. 8. It may be regarded as an extreme form of the ex- 
panding-sheaf formation. Beneath the living colony it is rotten from the burrowings of a sponge. 
Mr, Gardiner united it with Porites Ellice Islands 4. I do not, of course, deny the genetic 
affinity of the two forms, which is indeed probable enough, but it seems to me safer to keep 
on the right side of the facts, and describe the variations, leaving the affinities to be worked out 
in the future. See further under the heading P. EHilice Islands 4. 
The most remarkable feature in this Porites is the regular ring of twelve septal granules 
round the fossa of the deep calicles as if they took the places of the pali, which are always 
less developed in deep than in shallow calicles. They are, unfortunately, not well shown 
in fig. 6, because it is taken from above. Fig. 7 shows the character of the rapidly growing 
calicles all round the edge of the table top. 
a. Zool. Dept. 1905. 1. 19. 4, 
20. Porites Fiji Islands eg5, (P. Fidjiensis quinta.) 
[Kandavu, coll. H.M.S. ‘Challenger’; Wakaya Reefs, coll. J. S. Gardiner; British Museum. ] 
Syn. Porites crassa et crassistellata Quelch, Chall. Rep. xvi. (1886 ?) pp. 182, 183, pl. xi. figs. 2, 2a, and 
4, 4a, 
Description.—The corallum rises in the centre into a mound of small irregular nodules, 
while the edges of the stock creep outwards as a thin layer following the irregularities of the 
substratum. The creeping edge may be under 0°5 mm. thick. 
