REPORT ON THE TETRACTINELLIDA. 
87 
fusiform cells are associated with them, similarly arranged. The branching processes 
of the collencytes also take other directions, both concentric and oblique. The 
processes of the collencytes can be traced into connection with the epithelial cells on the 
one hand, and the choanocytes and the cells of the sarcenchyma on the other. 
Collenchyma also forms the spicular tracts, the coUencytes lying around the spicules. 
Near the cortex large stellate-cells, lying in vesicular cavities bounded by a definite wall, 
are frequent. 
The flagellated chambers vary from 0‘02 by 0‘0237 to 0‘0237 mm. by 0‘035 mm.; 
the choanocytes are from 0‘002 to 0’003 mm. in diameter at their base. 
Craniella jpulchr a, n. sp. 
Sponge subspherical, surface with numerous conules, bearing projecting spicules. 
Oscules, one or more in number, surrounded by longer conules than occur over the rest 
of the surface. 
S'picules. — I. Megascleres. 1. Somal oxea, fusiform, anisoactinate, obtusely pointed 
at the distal end, sharply pointed and almost filiform at the proximal end, 4 ’6 by 
0'0513 mm. in one specimen, 3‘93 by 0‘0513 mm. in another. 
2. Cortical oxea fusiform, 1‘2 by 0’0395 mm. 
3. Protrisene. Ehabdome cylindrical, tapering to a filiform extremity, cladi conical ; 
rhabdome 7’1 by 0'0225 mm. in one specimen, and 6'07 by 0’0225 mm. in another ; cladi 
0125 mm. long. 
4. Anatrisene. Ehabdome cylindrical, tapering to a filiform extremity ; cladome 
almost conical, somewhat pointed in front ; the axial fibre of the rhabdome continued 
into it up to its termination, i.e., for a distance of 0 ‘0158 to 0 ‘01 97 mm. past the origin 
of the cladi. Ehabdome 8'57 by 0'0165 mm. in one specimen, 7'678 by 0'0165 mm. in 
another; cladi 0'0434 by 0'0118 mm. 
II. Microscleres absent. 
Colour. — One specimen almost snow-white, the other cream-coloured with a tendency 
to brown. 
Habitat . — Station 163a, off Twofold Bay, Australia, April 4, 1874; lat. 36° 59' 8., 
long. 150° 20' E.; depth, 150 fathoms; bottom, green mud. 
Remarks. — This sponge is very similar in most characters to Craniella simillima, 
Bwk., but is distinguished by the considerably greater size, both in length and breadth, 
of the oxeate spicules, and by the greater number and smaller size of the conules. There 
are two specimens of the species, both dredged together, but differing somewhat in general 
appearance. The larger, which measures 31 mm. in average diameter, has three oscules, 
and its conules are coarser and more rigid than those of the smaller form, which measures 
