48 



DAWSOX AND HINDB 



comiioscd of somewhat loosely arrauged fascicles of elongated overlappiug spicules, and 

 the spiciiles of the slender transverse fibres are as a rule disposed in a single series. From 

 the outer surface of the siDonge, numerous spicular rays project outwards at right angles. 

 The sponge appears to have been anchored by a basal prolongation of the longitudinal 

 strands. Owing to the present compressed condition of the specimens it is difficult to 

 determine the original form of the constituent spicules. Some of the elongated longitu- 

 dinal spicules may be merely simple rod-like forms, others are clearly cruciform and 

 their transverse rays form the cross-fibres. The spicular rays which form the projecting 

 bristles of the svirface may be the free distal rays of normal hexactiuellid spicules, but 

 only these iwojectiug rays can now be clearly distinguished ; the others are merged in 

 the longitudinal fascicles. 



The general structure of the skeleton resembles that of Cyathospongia, Walcott, but 

 it is characterised by the presence of the projecting surface rays. The mesh is also of a 

 looser character than in Cyathospongia and its arrangement in quadrate areas is only 

 faintly recognisable. 



8. — ACANTHODICTYA HISPIDA, Hinde. 



(Figs. 18 and 19. PI. Ill, fig. 8.) 



Fig. 19. — Acanthodictya lii/pida. — Portions enlarged x 5, showing 

 framework and cruciform and protective spicules. 



Fig. 18. — Acanthodictya hispida. 

 Eestored. 



The examples of this species are apparently nearly cylindrical tubes from 30 to 50 mm. 

 in length, and about 12 mm. in width. The longitudinal fascicles are about 1 mm. apart 

 and the transverse fibres from 1 to 2 mm. distant from each other. The projecting spicu- 

 lar rays of the surface are only seen in these compressed sponges at the lateral margins as 

 a sort of fringe. The free rays are somewhat thickly set ; they vary from 5 mm. to o mm. 

 in length ; the longer forms in some instances occur at regvilar intervals, probably at the 

 angles of the mesh, and between these are the shorter rays. The extremities of many of 

 the larger forms are slightly swollen or club-shaped, but it is uncertain whether this is 



