46 MADREPORARIA. 
18, Porites Fiji Islands (948, (P. Fidjiensis tertia.) (Pl. IIL fig. 5; Pl. XIII. fig. 7.) 
[Wakaya, coll. J. S. Gardiner; British Museum.] 
Description —The corallum forms thin, closely encrusting plates, from the surface of 
which there rise smooth, rounded mammille, 1 em. high and 1°5 em. thick. There is a large 
mammilla in the middle of the stock, with attempts to form others. The edge of the colony 
above the epitheca consists of a zone of incomplete calicles. 
The calicles are small, about 1 mm. in diameter, as conical depressions. The walls show 
a thin median ridge consisting of a row of minute frosted granules; these rise from smooth, 
flat flakes which slope slightly downwards on each side into the calicle. The septa near the 
walls are broad tongues of the wall-flakes, and, when long, with jagged edges; each carries a 
frosted granule near its extremity ; these are the septal granules and usually rise on the shorter 
tongues, which project from the top edge of the wall-flakes, while the pali most frequently rise 
from longer tongues of a lower level. The formula appears to be that shown on Diagram E, 
fig. 3, but it is very irregular. The four principal pali are the best developed, but none rise 
higher than the septal granules, or are distinguished otherwise than by position. The fossa, 
compared with the size of the calicle, is large and deep in the oldest stock. A minute 
columellar tubercle can sometimes be seen deep down. 
There is one large specimen encrusting a Pinna; it is 7em. across. The symmetrical boss 
in its centre may indicate some foreign object grown over, but it strongly suggests the possi- 
bility of the stock being the explanate base of some branching Porites. 
Partly covered over by the large stock (a) is a smaller one (4), which is thinner, and its 
calicles have not the deep central fossa; whilea minute third stock (c), only 1 cm. in diameter, 
bleached and detached from the Pinna, shows that in the shallow calicles of very young 
colonies the radial symmetry is much more pronounced than it is in the deep calicles with 
their tiers of septal tongues. 
a. Large stock on Pinna, with central boss. \ Zool. D 
? : t. 1904. 10. 17. 17. 
b. Small stock on Pinna, partly covered by a. air we S va 
c. Minute bleached stock, detached. Zool. Dept. 1905. 1. 19. 3. 
19. Porites Fiji Islands 44, (P. Fidjiensis quarta.) 
(Pl. III. figs. 6, 7; cf. Pl. XIII. diagram fig. 8.) 
[Wakaya Reef (lagoon), coll. J. S. Gardiner; British Museum. ] 
Syn. Porites trimurata (partim), Gardiner, Proc. Zool. Soc. (1898), p. 270. 
Description.—The corallum forms massive cakes, some 3 cm. thick, with flat and gradually 
expanding tops. The upper surface is scored with shallow valleys, but the intervening mounds 
are low. The edge of the table-top is smooth and round, the colony extending some 2 cm. 
under the projecting edge. 
