SPONGES.-HALLMANN. I^j 



The largest specimens attain a height of 20 mm. The colour 

 of the living sponge is bright scarlet." To this it may be 

 added that the surface is sometimes free from conuli, and that 

 the colour in alcohol is brownish-grey. The largest which I 

 have seen is 15 mm. in diameter and 5 mm. in height. Oscula 

 have not been observed. 



The diagnosis contains pretty well all which need be said 

 concerning the skeleton. The basal layer of spongin is densely 

 echinated with erect acanthostyles. Columns of oxea, free 

 from echinating acanthostyles, such as are characteristic of 

 the preceding variety, have not been observed. Occasionally 

 the coring oxea at the extreme upper extremity of the fibres 

 spread out penicillately and form a sub-dermal tuft, but as a 

 rule the character of the fibre remains unaltered quite to its 

 point of arrival at the dermal membrane. The interstitial 

 megascleres, which are almost exclusively acanthostyles, are 

 fairly abundant. Oxea external to the fibres are extremely 

 rare except (occasionally) immediately beneath the dermal 

 membrane. The dermal skeleton is similar to that of the 

 variety pitmila. 



Megascleres. — 



(i.) The oxea vary in length from about 160 to 200 ;< ; the 



stoutest are 5 p in diameter. 

 (ii.) Ihe principal acanthostyles attain a maximum size ot 



ibo X S /(. 

 (iii.) The dermal acanthostyles vary in length from about 



60 to 80 ^ and do not exceed 6 ;/ in diameter. 



Microscleres. — 



The chelse, which resemble those of the variety levis, are 

 12 to 16 }( long. 



Loc. — Port Jackson (Austr. Mus. Coll.). 



Gexus Echinodictvlm, Ridley. 



EcHixoDiCTViM ELEGAXs, Leucleufchl. 



(Plate xxiii., fig. i, and fig. 35.) 



1888. Kalykenieron elegans, Lendenfeld, Austr. Mus. Cat. 

 Sponges, 1888, p. 216. 

 Kalykenteron silex, Lendenfeld, Loc. cit., p. 217. 

 1901. Thalassodendron typica, Whitelegge (nou Lendenfeld), 

 Rec. Austr. Mus., Iv. , 2, 1901, p. 86. 

 Sponge lamellar, usually vasiform, subsessile. Sur- 

 faces rarelv quite even, the outer, and sometimes to a 



