AUSTRALIAN PORITES. 141 
trabecule; seen from the side, they are fenestrated, The septa start rather deep down 
beneath the top edges of the wall, but rise to form a rather uncertain ring of small septal 
granules, within which ring, the tall, rod-like pali rise as a conspicuous oval ring, in complete 
formula B, fig. 3, p. 19. The elements of the triplet are smaller than the principals, but 
arranged symmetrically on the oval. The columellar tubercle does not rise to the height of 
the pali, and is a little obscure, but is mostly flattened, and sometimes divided into two. The 
interseptal loculi are deep and conspicuous when the calicle is looked at from above, but 
the frosted sides of the septa prevent them from being large. 
The cross section shows a very regular and rather close trabecular system. There is a 
lamellate axial reticulum, which appears at the tip in calicles of the well-known type, 
ef, Pl. XVI. fig. 6 (P. Great Barrier Reef 25). The colour of the unbleached coral is brown. 
This, unfortunately, is only a fragment. 
a. Zool, Dept. 92. 12. 1. 559. 
132. Porites Great Barrier Reef 4939. (P. Queenslandie nona et tricesima.) 
(Pl. XVIIL fig. 6; Pl. XXL. fig. 28.) 
[Great Barrier Reef, coll. W. Saville-Kent; British Museum. | 
Deseription—The corallum rises into an erect thin column, with a worm-tube* in its 
axis, Short, thick, scale-like knobs, rounded at their tips, cover the sides irregularly, the 
apex of the column being a knob 1°5 cm. in diameter. The column is 9 em. high, and 
3 to 3°5 cm. thick. 
The calicles are conspicuous, deepened, sub-cireular, only crowded when they open in the 
reticular eenenchyma at the apex round the worm-tube, slightly over 1 mm. in diameter. The 
walls round the tip are tall, ragged, very thin and reticular, the reticulum being lamellate or 
flaky, the flakes being mostly vertical and fenestrated. Lower down the walls gradually 
ficken, till near the base they are nearly 1 mm. across, and the reticulum is close, consisting 
of horizontal flakes, with a top edge of filamentous network ; in this a zigzag median thread 
may sometimes be recognised, but it is more often irregular, and the ends are mostly crisp 
echinulate granules, which are entirely absent from the lamellate skeleton at the apex of the 
column, The septa project at various levels down the sides of these walls; they are short and 
crisp; the septal granules are for the most part involved in the wall reticulum, but are 
frequently recognisable. The ring of pali, which are tall ragged spikes, is very large owing to 
the shortness of the septa. The formula is usually complete. The columellar tangle is large, 
with pores in it nearly as large as the interseptal loculi, which are very open. A central 
tubercle rises nearly as high as the pali. 4 
The section shows a radial arrangement of trabecule, which are stout, but wide apart. 
There are great numbers of tabulz, but no conspicuous development of an axial reticulum 
round the central worm-tube. Not only at the apex, but also at the tips of each of the lateral 
* The worm-tube is 2 mm. wide below, and nearly 4 mm. at the top, and open throughout 
its length. 
