KEPOET ON THE TETRACTINELLIDA. 
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rounded off at the end ; cladi simple, diverging almost at right angles from the rhabdome, 
conical, sharply pointed. Ehabdome 2‘18 by 0'055 mm., cladi 0’238 to 0'318 mm. long. 
4. Anatrisene (PI. XIV. fig. 4), rhabdome stout, conical, much attenuated proxi- 
mally, either exceedingly sharply pointed or rounded off at the end, cladi long, conical, 
sharply pointed, proceeding for a very short distance approximately at right angles to 
the rhabdome, and for the rest of their course recurved nearly parallel with it. Rhabdome 
3‘03 by 0'035 mm., cladi 0’16 mm. long; sagitta 0'16 mm., chord 0'16 mm. ; thickness 
of cladome 0’0478. 
II. Micrcfsclere. 5. Chiaster (PI. XIV. figs. 5, 6), no perceptible centrum ; actines 
very slender, rod-like, tylote, few in number, commonly from three to seven, O’OIG mm. 
in diameter. 
Colour. — Grey. 
Hahitat. — Samboangan, Philippine Islands ; depth, 10 fathoms. 
Remarks. — The single specimen of this sponge measures about 27 mm. in height and 
breadth ; the oscule measures 4 mm. in diameter, and leads into a cloaca about 6 mm. 
deep ; it is almost concealed by foreign bodies, which are attached by strong fibrous 
bands growing out from the cortex. The pores, from 0‘015 to 0'06 mm. in diameter, 
open into chones of about 0‘4 mm. in average diameter. The chones in their course 
through the cortex are crossed by several velar diaphragms, and continue by un con- 
stricted apertures into the large incurrent canals of the choanosome. 
Ectosome. — The cortex, about 0'8 to 0'9,5 mm. in average thickness, presents, as seen 
under a 1-inch objective, two well-marked and contrasted layers, the inner consisting of 
the deeply stained fibrous tissue usual in this position; and the outer, 0'32 mm. in 
thickness, of pale, unstained, polygonal cells, amidst which are embedded in places, sharply 
defined, rounded balls or clusters, from 0'06 to 0’22 mm. in diameter, of deeply stained 
polygonal cells. 
Under a higher magnification one makes out the following details. Beneath the outer 
epithelium (PI. XIV. fig. 7) is a layer from 0‘02 to 0‘04 mm. thick, consisting of collen- 
chyme traversed by numerous, tangentially disposed, small, fusiform cells about 0’04 mm. 
in length. Beneath this follows the layer of pale granular cells just alluded to ; these 
are now found to lie in oval cavities in a collenchymatous matrix, each in its' own cavity, 
which in the living state it probably completely filled. Although, owing to the abund- 
ance of these cells, the collenchyme is reduced to a mere intercellular network, it still 
retains its characteristic stellate collencytes, the branching processes of which, as they 
stain deeply, can be clearly traced extending through the partitions between adjacent 
granular cells. Long slender fusiform cells also extend through this tissue, sometimes 
singly and sometimes in fibrous strands. The granular cells of this curiously modified 
collenchyme are polygonal or irregular in outline, about 0'012 mm. in diameter, with a 
(ZOOL. CHALL, EXP. — PART LXIII. — 1887.) ElT 16 
