AUSTRALIAN PORITES. 115 
This coral stands alone in the character of its surface, being composed entirely of the tips 
of stout trabecule. The septa, the deep fossa, and the interseptal loculi can only be seen by 
bleaching. For another instance of remarkable trabecular development, see P. Great Barrier 
Reef 5, but the trabecule in that form rise as tall rods above the surface. 
a. Zool. Dept. 92. 12. 1. 310. 
101. Porites Great Barrier Reef (428. (P. Queenslandic octava.) (Pl. XIV. fig. 8; 
Pl. XXI_ fig. 4.) 
[Palm Island, coll. W. Saville-Kent; British Museum.] 
Description.—The corallum forms a swollen, flat-topped knob, narrowing towards the base 
and attached by a thick stalk. The top surface is covered with narrow, wave-like ridges 
running out towards the edge which projects furthest from the stalk. The living layer is some 
3-4 cm. deep: the edge is bent under round the stalk, and is closely adherent. 
The calicles are slight, very ill-defined depressions in a rough surface, from 1-1°25 mm. 
in diameter. The walls are not very thick, and consist of an irregular mass of large frosted 
granules. They are too irregular to form any sort of median ridge (except here and there in 
valleys or depressions). The septal edges are more regular and wedge-shaped, as rows of 
similar granules which tend to be square, or oblong transversely to the septum. Between 
these rows very narrow interseptal loculi, straggling and of uneven widths, run high up, and 
even, at times, between the granules, over the walls, while there is always a marked 
tendency for fine concentric furrows to appear between the wall and the septal granules, and 
again between the septal granules and the pali. These sharp, concentric furrows only become 
pronounced in the shallow calicles on the under surfaces. The four principal pali are large 
and conspicuous, and are easily rubbed off the dried corallum, The remaining pali are not 
always easy to distinguish from the septal granules, for none of them rise much _ higher. 
Compare the formula, Diagram E, fig. 3 (p. 19). The columellar tangle is dense, granular, 
and circumscribed, and an obscure central tubercle can be seen. 
The only specimen of this coral is 6 by 7 cm. aeross the flattened top. The whole stands 
6 cm. high, 2-3 em. of which is the dead base, thickly coated with calcareous alge. Upon this 
latter dead portion a very young colony apparently of the same coral can be seen as a small, 
nearly symmetrically hemispherical] knob. It consists of five calicles, but unfortunately, like 
the adult colony, it has suffered by the rubbing off of the large frosted granules from the 
upper edges of the walls, which, therefore, look somewhat smooth and dense. 
The peculiarity of the coral is that it appears as if it were entirely built up by an aggre- 
gation of frosted crystalline granules, and this appears even in the section across the base— 
which is the only section available for examination. 
a, With a very young colony attached to its base. Zool. Dept. 92. 12. 1. 351. 
Q 2 
