POLYNESIAN PORITES. 65 
section the corallum becomes nearly dense below the living layer, while the skeleton of the 
living layer itself is strikingly but very loosely trabecular, the individual trabecule being far 
apart and also tapering towards the surface. The horizontal elements are sparse. 
This coral is of exceptional interest because of the effects apparently produced by numbers 
of minute worm-tubes which open on its surface. They appear for the most part on the 
plateaux ; when they occur in any of the troughs they always seem to give rise to a develop- 
ment of the same proliferation of surface reticulum as that which constitutes the plateaux. 
It is impossible to avoid the suggestion that the coenenchymatous upheavals may be entirely 
caused by the presence of these foreign organisms. There is some reason to believe that the 
worm-tubes communicate with one another within the dense coral below the living layer. If 
the characters of the specimen are due to the presence of the worms, we have another case 
in which we are entirely at a loss to say what are the ordinary characters of the coral without 
the worms. It might, for instance, be a specimen of the next form in which the trabecule 
are pronounced, the pali tall, and the wall showing a strong tendency to rise into cenenchy- 
matous swellings. Against this suggestion we must note that the calicles of the next coral are 
larger and with a different septal formula, and the colour a light fawn instead of the pale 
grey of this coral, the living colony of which was green (see Gardiner, 1. c.). 
In addition to the principal colony, there is, attached to its basal crust, a very young 
stock in a small round saucer of epitheca, not 3 mm. in diameter. This shows the same 
tendency to form ccenenchymatous walls, though there are no worm-tubes. 
The only known specimen is in the Cambridge University Museum. 
42. Porites Ellice Islands q738, (P. Llliciana tertia.) (Pl. V. figs. 4,5; Pl. XI. fig..2.) 
[Funafuti (lagoon shoals), coll. J. S. Gardiner and W.J, Sollas; British Museum and 
Cambridge University Museum. ] 
Syn. Porites purpurea Gardiner, Proc. Zool. Soc. (1898) p. 269, pl. xxiv. figs. 1, d, 3. 
Deseription.—The corallum is massive and “monticulose,” its centre rising into a cluster 
of short, erect, irregular lobes or mammille from 1 to 1°5 cm. thick and up to 2 cm. high, 
sometimes forming together low hemispherical mounds, sometimes conical stocks 12 cm. high 
(Pl. XI. fig. 2) and 6 cm. thick at the base. There is a very pronounced edge formation, the 
living layer extending right down over the base; the thick edges are sometimes free and 
pendent, thinning rapidly to about 2 mm. 
The calicles (cf. Pl. V. fig. 5) crowded and conspicuous, and as if sunk into the upraised 
wall-reticulum ; they average about 1°25 mm. across, with many small buds appearing in the 
wall-angles. The walls consist of a bold flaky reticulum ; its flaky elements are especially 
conspicuous at the growing tips of the lobes, but on their steep sides the flakes are not so 
broad, and consequently are less visible; they are further obscured by the granulated or frosted 
tips of the trabecule rising all over the surface. The intra-calicular skeleton is very bold 
K 
