SPONGES FROM THE ABROLHOS ISLANDS. 49-9 
proniinencos which are sparsely scattered over both surfaces of the sponge. 
The colour in spirit is light brownish yellow ; texture tough, flexible, 
resilient. 
The skeleton consists of loose tracts of spicular fibre running longitudinally 
and confined to the middle of the lamella ; at right angles to these on 
both sides still looser and less well-defined fibres run, outwards towards the 
surface, where they terminate in loose brushes of spicules, which help to 
support the dermal membrane. 
Numerous loose spicules lie scattered everywhere between the fibres. 
There is a fair quantity of spougiii present, but so pale in colour that it is 
almost invisible in unstained preparations. 
Spicules: — Oxea (PI. 26. fig. 10a) ; usually slightly curved or angulated 
and tapering somewhat abruptly at each end to a sharp point ; measuring 
about 0'58 by 0'017 mm. when fully grown, but frequently shorter and 
especially more slender. These spicules occasionally become stylote, with 
one end broadly rounded off (PI. 26. fig. 10 b). 
Halichondria phakellioides seems to come very near to Halicliondria vela- 
mentosa (Hansen) Lundbeck [1902], a remarkable fact considering that 
the former is a shallow-water, sub-tropical form, while the latter is found in 
deep water in the Arctic regions. 
Register No. and Locality. "VI. 1, Sandy Isle. 
29. Chalina palmata (Lamarck). 
Sponffia palmata Lamarck [1913]. 
Chalina palmata Ridley & Dendy [1887 |. 
Cladochalina euplax Lendeiifeld [1887]. 
Chalina palmata Whiteleg-gp [1901]. 
? Cei-aochalina retiarmata Dendy [1 905]. 
There are three small, incomplete specimens in the collection. The sponge 
is of erect habit, and consists of irregular, digitate processes arising from a 
narrow base and sometimes branching. The surface is fairly even, slightly 
hispid, and has a distinctly reticulate appearance. The thin, transparent 
dermal membrane is pierced by numerous round inhalant pores, which vary 
considerably in size. The small, round oscula measure up to 2 mm. in dia- 
meter, and are for the most part arranged uniserially on the margins. Colour 
in spirit light brown : texture spongy, tough and fibrous. 
The skeleton arrangement agrees closely with that of Chalina palmata 
Ridley and Dendy [1887], except that the dermal reticulation of spicular 
fibre has a somewhat smaller mesh. 
Spicules : — Oxea ; short, slightly curved, gradually sharp-pointed, measuring 
about 0"07 by 0'004 mm., but often more slender. 
After re-examining the type slides of Ceraoclialiiia retiarmata Dendy 
[1905], we think this species may also be identical with Chalina palmata 
(Lamarck). 
3fi* 
