MR. H. N. MOSELEY ON THE STRUCTURE OF THE STYLASTERID2E. 
443 
Corallum of Errina labiata. (Plate 34, fig. 7.) 
The corallum occurs in the form of arbuscular multi-ramified masses, which have an 
extreme height, in the specimens obtained, of about 5 inches. The mass ot branches 
and branchlets has a tendency to form an irregularly flabellate expansion, which in the 
largest specimen obtained has a breadth of about 4 inches. The main stems, which 
are irregularly oval in section, being flattened in the plane of the flabellate expansion, 
have a longer diameter of about two-thirds of an inch. They, as well as the remainder 
of the corallum, are composed of a compact, hard, glistening, white, calcareous tissue. 
At their bases, this tissue spreads over and encrusts objects to which the coral mass is 
adherent. In one specimen obtained, the support thus fastened on is a large dead 
mass of Sporadopora dichotoma. The main stems have a surface which appears 
smooth and even to the naked eye, but when magnified is seen to be scored in 
all directions by small more or less tortuous canals, which in the recent state contain 
the superficial ramifications of the coenosarcal meshwork. In specimens in which 
certain regions of the main stems are dead and somewhat corroded, these scorings of 
the surface are much more conspicuous than on the recently living regions, and give 
the surface a roughly engraved appearance. The finer branches have a tendency to 
develope mostly on one face only of the flabellate expansion, one face of the main 
stems being frequently devoid of such branches. The branches and branchlets are 
nearly circular in section, and have an hirsute or finely spinous appearance. This 
appearance is due to their being beset all over their surfaces with small nariform 
projections, the wide openings of which are all turned towards the tips of the branches. 
These nariform projections vary much in form, being often drawn out into tubes 
opening by a slit-like mouth on the side next the tip of the branch, and frequently 
coalescing, especially towards the tips of the branches, so that two or three of the 
projections have a common base. 
These projections are the prolongations of the walls of the dactylopores beyond the 
main surface of the corallum. Their cavities, the pores, are simply tubular without 
any style, and extend for a short distance into the mass of the branch, on which they 
are situate in an oblique direction, in continuance of the oblique inclinations of the 
nariform projections. The dactylopore projections are very numerous and closely set 
towards the tips of the branchlets, more widely scattered upon the surfaces of the 
branches and almost absent on the main stems. 
Scattered over the surfaces of the branches and branchlets are the mouths of the 
gastropores, which are tubular cavities larger than the dactylopores, but with a similar 
oblique direction towards the axes of the branches, and are provided with a calcareous 
style, with a finely dentate surface (Plate 37, S T). The mouths of the gastropores are 
irregularly circular in outline, their margins being frequently broken and indented 
by the confluence with the pore cavities of the superficial channels of the surface of 
the corallum. The gastropores are frequently situate beneath the bases of the 
