REPORT ON THE TETRACTINELLTEA. 
429 
unchanged character. The broadening of the flattened ridges continues till each conule 
with its ridges becomes a wide polygonal plate, with denticulated or crenate margins, and 
the interconular spaces are reduced to narrow crevices between them. The extension of 
the conule in this fashion may proceed till the lobes of the marginal crenations fuse with 
those of adjacent conular plates, reducing the intervening crevices to a linear series of 
minute canals. With the final extension of the conule the scar-like appearance of the 
surface vanishes. 
These changes in the characters of the conules are related partly to the gemmation 
of the sponge, partly to the position of the oscule. Near the oscule, and I may add near 
the base of the sponge, the conules are usually of the plate-like form, possibly because 
in these regions there is a minimum of in streaming water, owing to fewer flagellated 
chambers occurring in their vicinity. Large pore-sieves are not required in these posi- 
tions, and the conules enlarge for support and protection. The connection with gem- 
mation is as follows : — The buds are first protruded at the ends of the conules, upon 
which they are at first sessile, but subsequently extended on the end of a stalk ; they 
then drop off and leave a flat scar behind, from the middle of which is sometimes pro- 
duced a short spicular style. The extension of the scar over the radiating ridges of the 
conule may be due to the base of the stalk being carried away by the bud, and such is, 
I think, the case in many instances ; in others it would appear due to the ajDpearance of 
fresh buds from the sides of the conule after the first have been formed and liberated. 
Several buds, mostly measuring about 1'5 by 0'9 mm. in length and breadth, are still 
adherent to many of the conules near the base of the sponge. Some of these were 
examined in serial sections, but in none was a trace of a flagellated chamber found. They 
are solid throughout, and present no other structure than is to be found in the outer 
layer of the cortex. In form they are generally oval, but produced at the distal end into 
tent-like projections, into which the strongyloxeas of the interior project. Beneath an 
investing epithelial layer follows a single layer of cells, each containing a chiaster like 
that of the adult sponge ; this is succeeded by a tissue composed in varying proportions 
of oval granule-cells and fusiform fibrillated cells. Near the exterior the granule-cells 
predominate, almost to the exclusion of the fibrillated cells ; in the interior the fibrillated 
cells, the granule-cells there occurring only sparingly scattered through the fibrous 
tissue. The granule-cells are about 0'012 to 0‘0158 mm. in breadth by 0’0198 mm. in 
length ; they consist of spherical, deeply staining, homogeneous granules, about 0‘0025 mm. 
in diameter. Spherasters are absent, and the strongyloxeas present no evidence of a 
trisene derivation. 
The specimen from Samboangan is free, with a rounded base, 31 to 28 mm. in 
diameter by 31 mm. in height ; the summit is raised into a rounded conical eminence, 
formed of closely apposed lozenge-shaped conular plates, which conceal the oscule 
(PI. XLIV. figs. 1, 3). The texture is much firmer than that of the preceding specimen. 
