72 



C. HEDLEY. 



infests it, while the exterior is encrusted 

 with a sponge, perhaps a species of Halis- 

 arca. 



The Eklonia zone is most difficult to 

 explore and its fauna is therefore yet 

 imperfectly known. Besides the species 

 that adhere to the ground there is a con- 

 siderable fauna living on the stems or 

 leaves of the plants themselves. A 

 handsome, nacreous shell, Cantharidus 

 eximius, is called the Kelp-shell, because 

 of its exclusive resort. In contour it 

 differs from its relations that live on the 

 stones, for it is moulded in easy curves 

 that the water cannot grip, and so it sits 

 ever afloat on the swaying bands of kelp. 

 An olive-green isopod, Amphoroidea aus- 

 traliensis, never swims, though structur- 

 ally well fitted for that exercise, but clings 

 tenaciously to the stalks of Phyllospora 

 comosa. Another isopod which crawls 

 about on the weed is Idotea peronii with a long body like 

 a millepede. 1 This epiphytic fauna is considerable and 

 would be a profitable field for study. It might be expected 

 that this fauna would travel far on drifted weed, but I 

 have no evidence that it does so. 



Mr. T. Whitelegge, who carefully examined the Eklonia 

 zone at Maroubra, has kindly given me the following notes. 

 Two sponges of industrial possibilities, Euspongia illawarra, 

 and E. zimmocea, occur alive under rock ledges at low tide. 

 Attached to the roots of sea- weeds or to ascidians are the 

 bryozoa, Amathia tortuosa,Ascopodaria fruticosa, Crypto, 

 zoon wilsoni, and C. contretum. Among the Alcyonaria 



Fig. 38. Boltenia 

 australis, natural 

 size. The sea-tulip 

 from the Eklonia 

 zone of the ocean 

 reef. 



1 Whitelegge, Eec. Austr. Mus., iii, 1899. p. 156. 



