56 MADREPORARIA. 
islands of the Fiji group—viz. No. 6. It shows a faint thin ridge running along the middle 
of the otherwise broad, flaky walls, but not sufficiently pronounced as to give the impression 
shown in Dana’s figure. 
Among the specimens from the most northerly island of the group, Rotumah, are 
encrusting forms whose walls show at the surface like a reticulum of thin ridges, but in no 
case are the calicles shallow; they are, on the contrary, often so deep that the pali are hardly 
developed. 
We must wait for further material from these islands before we can hope to obtain any 
certain light upon either of these forms. 
There is a specimen in the Paris Museum from the Collection “ Agassiz,’ and labelled 
P. reticularis I. Fidji. But this shows no features sufficiently marked as to remind one of 
Dana’s figure. 
33. Porites Fiji Islands 418, (P. Fidjiensis octavadecima.) (PI. IV. fig. 1; 
Pl. XIII. fig. 10.) 
[Rotumah, reef near Solkopi, coll. J. S. Gardiner ; British Museum. | 
Syn. Porites viridis var. apalata (partim) Gardiner, Proc. Zool. Soc. (1898) p. 268. 
Description.—The corallum is thin, encrusting, of quite irregular outline, following the 
irregularities of the substratum, and even folding under. Colony about 1 mm. thick at the 
edges. 
The calicles are polygonal and deep, very variable in size, mostly small, but with groups of 
larger ones up to 1°25 mm.; these are usually congregated on the rounded elevations of the 
surface. The walls are characterised by their sharp ridges, which are smooth and thread-like 
or wavy and irregular, variously but not strikingly denticulate. Indications of the septa 
appear immediately below the edge of the ridge as small blunt points, sloping downwards into 
the fossa; these lengthen very gradually, the septa being represented by vertical rows of blunt 
points or knobs, irregularly fused together. The typical fusion of the septa with one another 
is only indicated. There are no pali, the base of the fossa deep down being occupied by a 
rather coarse reticular columellar tangle. 
This is the description of the small encrusting specimen which Mr. Gardiner mentions 
(1. c. p. 269). It may be that Mr. Gardiner’s suggested affinity between this and the types of 
his var. apalata (see next heading) is correct, but the striking differences between the two 
ought to be more clearly emphasised. F 
In favour of Mr. Gardiner’s view that they are genetically related, we note that they come 
from the same locality and are of the same colour, the living polyps being a bright dark green 
—the dead skeleton a pale ashy grey—while some of the specimens (4 and @) of the next form 
show also the encrusting method of growth. Even a resemblance between the calicles can be 
traced. 
I would call attention to the character of the septa and the absence of pali in the deep 
calicles of this form (compare P. Hilice Islands 10). 
a. Zool. Dept. 1905. 1. 19. 6. 
