78 MADREPORARIA. 
of a reticulum of a very variable texture, here finely filamentous with open meshes, there coarse 
and apparently built of thick, flat, spiky or nodulated flakes, but mostly with neat round pores. 
The septa can sometimes be traced into the reticulum on the top of the wall, but they usually 
begin in large echinulate wall-granules, not very clearly separated as granules either from the 
wall or from the small septal granules, which sometimes link them to the pali. The three 
granules when run together make a thick, tapering, echinulate septum, The ring of pali is 
complete but not conspicuous; the principals are irregularly echinulate. The fossa is small, 
the central tubercle large, and flattened in the directive plane. All the skeletal elements thicken 
very rapidly, and this thickening can be seen in a side view of the pali and other projections, 
and still better in vertical sections; the trabecule thicken below so as almost to obliterate the 
intervening spaces, and thus to form a nearly solid mass. This rapid solidification of the coral 
appears to be correlated with the shallowness of the calicles. 
There is no other known Porites from the Ellice Islands group at all like this. 
The small size of the stock and its irregularity suggest that it was struggling with un- 
favourable conditions ; if so, we do not at all know how these have affected the calicle skeleton. 
But this of course is the standing difficulty, and makes all attempts at definitive systematic 
arrangement impossible until more work has been done on the reefs. 
55. Porites Ellice Islands q716, (P. Elliciana sextadecima.) (PI. VII. fig. 8; 
Pl. XIV. fig. 24.) 
[Funafuti,* coll. W. J. Sollas; British Museum. ] 
Description.—The corallum rises as thin, crooked, nodulated stems, here rounded, there 
flattened, from 1°5 to 2 cm. thick. The complete height and the form of clustering are 
unknown. From the sides of the stem thin slightly compressed branchlets arise, and fork at 
about 2 cm. from the main stem. The living layer is at least 5-5 cm. deep. 
The calicles are sub-circular, flush with the surface, 1 mm. in diameter. The walls are stout 
but simple near the tips, gradually thickening down the stem, becoming a reticulum so dense 
that where the mosaic of surface granules is rubbed off it looks as if built of solid flakes parallel 
with the surface. The septa are in complete formula and very regular, the top edge of each 
consisting of two large granular thickenings joined by narrow connections; these are the septal 
granules and the pali; the latter are either as in Diagram E or F (fig. 3, Introduction, p. 19). 
The ventral directive sometimes runs into the flattened tubercle, which is large and rises to the 
height of the pali. The tubercle and the pali are often joined by thin strands. The interseptal 
loculi are conspicuous and deep in the upper calicles (see Pl. VII. fig. 8), but much fainter round 
the lower parts, where the surface tends to become a close mosaic of granules arranged in regular 
circular patterns, 
The section shows rather stout trabecule, the concentric elements being feebly but 
uregularly developed. 
* See observation at head of Ellice Islands group. 
