118 MADREPORARIA. 
thin and loose; in section, the trabeculae are seen to be short but far apart, with a great 
development of the horizontal elements. The colour of the unbleached coral is a sepia, 
with a greyish bloom caused by the glassy granules. 
This Porites is one more of those with the horizontal skeletal elements specially developed. 
Its growth-form is different from that of any other Porites yet known. 
a. Zool. Dept. 92. 12. 1. 348. 
105. Porites Great Barrier Reef (42,12, (P. Queenslandie duodecima.) (PI. XIX. fig. 6.) 
(Palm Island, coll. W. Saville-Kent ; British Museum. ] 
Description.—The corallum rises into thick, smooth, flattened, wavy or curving stems, 
which seem to fork dichotomously at about every 2 cm. of their length. The tips of the 
branchlets flatten greatly, and expand prior to forking. The stem may be 2°5 by 1°8 cm. in 
long and short diameters. The branchlets, which are nearly cylindrical, except at their tips, 
are 2 cm. long and 0°5 cm. thick. 
The calicles are very obscure in the smooth, finely granular, almost velvety surface. 
They appear only as dark stains, about 0°75 mm. in diameter, and quite flush with the surface. 
The walls are broad, of irregular thickness, 0°5 mm. or more, flat, apparently nearly solid, 
and smooth. Their tops are covered by numbers of flattened granules, without any recog- 
nisable order, except that some are the wall granules at the roots of the septa, and from 
these others may run in straggling lines across the wall. Within the calicle, as is usual in 
these branching trabecular Porites, only large, rather closely packed, granules can be seen. 
The outer ring of septal granules is almost in contact with the walls. The pali are large and 
very close to one another and to the septal granules. The formula is rare and seems mostly to 
be like H, fig. 3 (p. 19). A central tubercle rises in the fossa as high as the pali. 
The cross section shows a very close cross network consisting of stout radial trabecule, 
not very crowded, joined by concentric rings, also stout, and close together, but perhaps not 
quite so developed as the trabecule. 
Both in growth-form and size of calicle, so far as known, this branching form of Porites is 
unique. 
a. Zool. Dept. 92. 12. 1. 309. 
