POLYNESIAN PORITES. 59 
We have here a most instructive series of five specimens. Had the extraordinary 
differences seen in them (ef. figs. 2, 3, 4) been distributed so that each specimen had but one 
uniform type of calicle, they would necessarily have all been described separately. But the 
calicles are not uniform over any of the specimens, and the two extremes of wall formation are 
found on one and the same colony. 
35. Porites Fiji Islands (9420, (P. Fidjiensis vicesima.) (Pl. IV. fig. 5.) , 
[Rotumah (boat channel"), coll. J. S. Gardiner ; British Museum. |] 
Syn. Porites parvistellata (partim) Gardiner (? Quelch), Proc. Zool. Soc. (1898) p. 272. 
Description.—The corallum forms a massive, roughly conical mound. The top is round, 
and the sides slope gently outwards. The specimen shows no free edges. 
The calicles are small but conspicuous, polygonal, averaging about 1 mm. across. The 
wall, which is not thick, is yet strong looking, and, when not actually reticular, is almost 
solid, with a sharp median ridge composed of fused trabecule; beneath this ridge the wall 
appears to be thickened by the broad bases of the septa, usually without the formation of 
any reticulum ; here and there, however, parts of rings of synapticule appear like portions of 
an inner wall. The septa are smooth and short, often too short to meet; all stages in the 
formation of the typical septal formula can be seen. The fossa is deep, round, and seldom 
obscured by the presence of a columellar tubercle, The interseptal loculi are round and 
conspicuous. 
It is quite possible that this Fiji form may be closely allied genetically with Quelch’s 
small calicled form from the New Hebrides, but their structural differences, which, if we wish 
to get any insight into the variations of the genus, it is our business to emphasise, are very 
great. The calicles of the latter are rather smaller, and their walls more uniformly fragile 
and porous, with ragged, irregular denticulation. The septa are longer, much thinner, and more 
fragile. See the description and figure of P. New Hebrides Islands 1 (p. 81, Pl. VIII. fig. 1). 
In his original description, Mr. Gardiner mentions two specimens as coming from 
Rotumah. This is apparently an oversight; the second specimen is P. Ellice Islands 10 (for 
the description and figures of which, see below, p. 73). 
a. Zool. Dept. 1905. 1. 19. 9. 
36. Porites Fiji Islands (94)21, (P. Fidjiensis prima et vicesima.) (PI. IV. fig. 6; 
Pl. XIII. fig. 12.) 
[Rotumah (boat channel * ), coll. J. S. Gardiner; British Museum.] 
Syn. Porites alveolata Gardiner (non M.-E. & H.), Proc. Zool. Soc. (1898), p. 268, pl. xxiv. fig. la. 
Description.—The corallum is massive, and forms smooth, rounded lobes with thin edges, 
which are closely adherent and bending under. 
* Its greatest depth at low tide is 8 ft., see Gardiner’s account of the reefs in Proc. Camb. 
Phil. Soc., ix. (1898) p. 441. 
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