110 . MADREPORARIA. 
This Porites is quite different from all those yet described. It is especially interesting 
because it shows a tendency to produce the same kind of calicle as that which is typical of 
explanate Goniopores, a type which I believe comes nearest to that of the ancestral form 
(ef. Vol. IV. Introduction, p. 19, with Pl. XI. fig. 1). 
a. Zool. Dept. 92. 12. 1. 269. 
95. Porites Great Barrier Reef (492. (P. Queenslandie secunda.) 
(ELVES fie) PL exoxay fasta) 
[Capricorn Islands, coll. W. Saville-Kent; British Museum. ] 
Description—The corallum rises into small, round, erect columns, close together, nearly 
smooth, and with rounded tops. The columns are from 4-5 cm. high and from 1-2 em. thick. 
In large stocks they may all fuse together to form a stout, slightly expanding, fluted column, 
the top surface of which shows the several columns of which it is composed. The living layer 
extends 5-6 cm., the lower edge being hardly free, and with stout epitheca. 
The calicles tend to be large, 1°5 mm., shallow, open, and rounded; on the top of the 
columns they open in a beautiful, delicate, almost filamentous stroma. The walls of the typical 
calicles on the sides are not thick, but tend to be reticular here and there, e.g. in the angles. 
They are otherwise thin irregular rows of loose, even ragged trabecule, sometimes thickened 
by the broad bases of the septa. The septa appear just below the edge as stout coarse granules, 
but they project very irregularly and at different depths below the wall; sometimes they 
run out, rod-like, to join the pali high up, at others only deep down in the fossa. Where 
he wall is thickened, traces of the inner synapticular ring are apparent. They fuse in the 
typical pairs. The pali are like tall bristles rising freely from the depths of the calicles, 
except where here and there one is attached as described to the wall by a septal rod. The 
ring of pali is large, loose, but conspicuous, nearly reaching to the height of the wall in 
the complete number (B, fig. 3), and all of nearly the same size. The fossa is deep, the 
columellar tangle not well seen from above as an open reticulum of few strands; the central 
tubercle is minute and below the level of the pali. The section shows the ragged trabecule 
very loosely arranged. The colour of the unbleached coral is dark sepia. 
There are two specimens of this Porites. One consists only of three columns, the other 
is fused into a mass of five or six. The smaller one is from Capricorn Islands, the locality of the 
larger is given merely as “The Great Barrier Reef.” In this latter the calicle skeleton is a 
little more frosted and thus less conspicuously open, the interseptal loculi being smaller. There 
can be very little doubt that these two corals are of the same kind, and in all probability both 
came from the Capricorn Islands. 
On the larger specimen there is a young colony of Alveopora within its epithecal saucer, 
but greatly contorted by a calcareous alga. 
a, Zool. Dept. 92. 1 
; 2. 1. 350. 
b (most probably also from Capricorn Islands), Zool. Dept. 92. 12. 1. 524. 
