226 MADREPORARIA. 
short processes tend to be moniliform. There is a tendency to develop a smooth epithecal 
pellicle at the edges, where the colony is dying away. 
The calicles are from 1 to 1*2 mm. in diameter, conspicuous on the more recent knobs, 
where the intra-calicular skeleton is thin, and the calicles appear as dark stains; nearer the 
central body they become more and more difficult to distinguish on the perfectly smooth, 
velvety surface. The walls are thick, with only occasional signs (namely, near the tips of the 
knobs) of any median ridge; they seem nearly solid, and appear to be composed of crystalline 
granules, the details of which are difficult to unravel. the surface being sprinkled with smaller 
and more delicate granules. In the uppermost calicles the intra-calicular skeleton shows this 
same delicate character, only the walls appear solid just beneath the surface ; but lower down 
the whole seems to become solid, with the finer granules giving a velvety surface. The radial 
symmetry can be traced both in the young calicles opening in the straggling, angular reticulum 
on the tops of the knobs, and in the more inconspicuous calicles ; but it is greatly obscured. 
There are no pali and no fossa visible to the naked eye. 
The section shows a radial arrangement of short trabeculee, nodulated and stout, and 
ending in fine jagged points at the surface. The pores are rounded, and largest near the 
periphery. The colour is bright buff. 
The characters of the skeleton of this specimen (a) are very difficult to define. The 
granules are like minute jagged crystals of gum-arabic, and their translucency makes it very 
difficult to see them. Essentially the same character is found in both specimen 6 and in 
P. Providence Islands 1, but the details of structure are here somewhat more crisp and 
pronounced. 
This specimen seems to have come to anchor, for one-half of it was dead when it was 
found, and had secreted a film which allowed the surface granules to show through. The 
lower half may, indeed, have been buried in the sand. 
a. Zool. Dept. 82. 10. 17. 207. 
Description of specimen b.—The corallum is free, branching, and consists of a central 
body, from which long, very irregular, bent, angular and nodulated stems, covered with knobs 
and small mammillate processes, radiate in all directions. The living colony is largely 
confined to the processes. 
The calicles are from 1—1°2 mm. in diameter, shallow, but as distinct, concave depressions. 
The walls everywhere rise as thin, sharp, median ridges, seen sideways, of scattered crystalline 
granules; these granules are the fine glassy tips of trabeculae. There is everywhere a 
tendency for the wall to be thickened regularly by an inner synapticular wall, which, owing 
to the frosted crystalline character of the skeleton, easily becomes irregular and solid-looking. 
The septa are symmetrical and end in a low ring of pali, which can be seen with the naked 
eye surrounding a very minute fossa, The pali are small, very frosted, and generally in 
the complete formula. 
The section and the colour of the coral are similar to those of a. 
