438 
placed vertically towards the surface, contribute to make the sponge 
hispid; several of the oxea are also placed pell-mell in the cortex, 
tending, however, to form brushes. In the interior of the sponge- 
body oxyasters are assembled in greater numbers, especially in 
places, where megascleres are only scantily found. 
Spicules. 1. Dichotriaenes (fig. 2a); shaft generally thickest 
at the base, then for a smaller part even, and then again tapering 
towards the sharp-pointed apex; length varying from, say, 1500 — 
3000 (i by a thickness of about 50 The primary cladi are* 
issuing from the shaft at the usual oblique angle, the secondary 
cladi, of about the same length as the primary ones, are mainly 
directed perpendicularly towards the shaft; they are conical and 
generally rather sharp-pointed; entire width of the cladome about 
350 some of the dichotriaenes, however, have cladomes, which 
are only very slightly branched, and, as a matter of faet, all inter- 
mediate forms between dichotriaenes and plagotriaenes oceur. 2. 
Plagotriaenes (fig. 2b); generally more siender than the dicho¬ 
triaenes; length the same, but thickness only 30—40 3. Oxea 
(fig. 2 c); slightly curved, thickest in the middle, tapering evenly 
to the sharp-pointed apices; 1200—3000 x 45 /i' or less. 4. Cor- 
tical oxea (fig. 2d); straight, thickest near the middle, rarely 
just in the middle, tapering evenly to the sharp-pointed apices; 200 
—400 X 10 5. Oxyasters (fig. 2e); with from 4—10 long, 
sharp-pointed, conical rays,. only a small body; entire diameter 
26—32 
Stelletta sandalinum nov. spec. 
(Fig. 3, a—e.) 
Slipper Island; the coast, at low water. 20/XII.1914. 
2 specimens, only fragments, flesh-coloured, somewhat flattened, 
55 mm in largest diameter, about 15 mm thick. The sponges are 
unfortunately preserved in formaline, therefore rather macerated. 
Where the surface is intact it is coarsely hispid. No oscula are to 
be seen. Through the dermal-membrane are seen the ends of nume- 
rous narrow canals giving the sponge an appearance, when seen 
through a pocket lens, as if it were pricked with a needle all over. 
The cortex is thick and rather hard, being built up of the densely 
packed brushes of plagotriaenes; it is up to 2 mm thick. 
