52 On Sponges from South Australia. 



account of its spiculation. It seems to be very plentiful on 

 the south coast of Australia, as there are several specimens of 

 it in Mr. Wilson's collections, both wet and dry. 



Group 7. Halichondeina. 



6. Tlalichondria hirotulata, T. H. Higgin (' Annals,' 1877, 

 vol. xix. p. 296, pi. xiv. figs. 11 and 12). 



Ols. This sponge, which is characterized by its dark 

 tnadder-red colour when dry, is also stated by Mr. Wilson to 

 be " chocolate-black " when fresh, so that it does not lose 

 its colour by keeping, either wet or dry. The birotulate 

 spicule, after which it has been designated, is also peculiar 

 in form, and so small that it is apt to pass unnoticed in the 

 microscopic specimen when wet, but comes out well in a 

 fragment that has been mounted in balsam. On the Austra- 

 lian coast it appears to be very common, occurring in the late 

 Dr. Bowerbarik's collection from thence, now in the British 

 Museum, in large staghorn-like branched specimens. 



7. Halichondria I'sodicti/ah's, Carter (' Annals,' 1882, 



vol. ix. p. 285, pi. xi. fig. 2). 



Ohs. The specimens of this sponge in Mr. Wilson's collec- 

 tion are massive and lobed, with large vents scattered over 

 their surface, stated, when fresh, to have been " slate-brown " 

 in colour. The princi])al difference between their spiculation 

 and that of Halichondria incrustans (of which H. isodictyalis 

 hardly amounts to more than a variety), is the spine^es's con- 

 dition of the acuate. It appears to be almost world-wide in 

 distribution. 



8. Tedania digitata, Gray (Proc. Zool. Soc. 1867, May, 



p. 520). 



Ohs. Beniera digitata was Schmidt's earliest name for this 

 species (Spong. Adriat. Meeres, 1862, p. 75, t. vii. fig. 11), 

 Avjiich he afterwards changed to " Tedania^ Gray" (Spongf. 

 Atlantisch. Gebietes, 1870, p. 43). 



There are several specimens of Tedania digitata in Mr. 

 Wilson's collections whose form is massive and lohate, said, 

 when fresh, to have been " orange " in colour. All are 

 characterized by the same spiculation, viz. : — 1, a smooth, 

 stout, skeletal acuate; 2, sub-skeletal, fusiform acerate, in- 

 flated and scantily spined at each end, the " tibiella," first 

 so named and described in the ' Annals ' (1881, vol. vii. 

 p. 369, pi. xviii. figs. 9, h) ; and 3, a very fine, pointed 

 acerate, microspined all over. 



