134 MADREPORARIA. 
g. Isa free nodule, with the top of a previous growth protruding between the edges of 
the living colony where the stalk ought to be. Zool. Dept. 97. 3. 9. 216. 
h. A rounded nodule, with edges creeping (some under, some outwards) over the irregular 
mass of rotten coral which formed the substratum. Zool. Dept. 82. 2. 23. 148. 
123. Porites Great Barrier Reef (4930. (P. Queenslandic tricesima.) 
(Pl. XVII. fig. 6; Pl. XXI. fig. 22.) 
[Torres Strait, coll. A. C. Haddon; British Museum. ] 
Description.—The corallum forms thick flattened cakes of irregular outline, running out 
here and there into large rounded lobes. The surface is nearly smooth, but with a few slight 
concave depressions, quite irregular, and forming no system of valleys. 
The calicles are polygonal, large, 1-25 mm., flush with the surface except for a thin raised 
wall, which forms a sharp reticular pattern over the whole surface. The wall is a low mem- 
branous thread, very echinulate and generally straight, the irregularities not showing any 
zigzag pattern. There are no traces of an inner synapticular wall at the surface, although 
deep down they can be made out; the septa are long and straggling, very thin, slightly 
bent, and here and there thickened by lateral echinulations. These irregular thickenings 
occasionally appear as a ring of small septal granules halfway between the wall and the pali. 
This ring, indeed, becomes conspicuous on the lateral calicles where the skeletal elements are 
all thicker and the skeleton itself more compact. The pali form rather a large ring of eight 
very frosted granules or plates, which rise from a light reticular tangle, with a flattened 
central tubercle. The lateral calicles are very symmetrical and compact arrangements of 
neat rings of large frosted granules, which are the tips of stout trabecule, with small 
intervening pores. 
The colour of the unbleached coral is an ash-grey. 
There is one specimen with a peculiar cake-like growth. For some time I hesitated as to 
whether this might not be a variety of P. Great Barrier Reef 23. But the complete absence 
of any inner synapticular ring forming a second wall, and the difference in growth-form, compels 
me to keep them separate. They have, however, the shallow polygonal calicles, with raised 
thread-like wall and central boss of pali, in common. 
a. Zool. Dept. 97. 3. 9. 224. 
124. Porites Great Barrier Reef (4931. (P. Queenslandie prima et tricesima.) 
(ASV ho aie Pl Xexa, figs '2.08) 
[Torres Strait, coll. A. C. Haddon; British Museum. ] 
Description.—The corallum rises from a small initial colony, about 2°5 cm. in diameter, 
into a smooth rounded mass, the calicles in the vertical section spreading out in a wheat- 
sheaf arrangement. 
