KEY TO THE AUSTEALIAN GENERA. 247 



f Fibres pithed 58 



57 \ 



(■ Fibres solid (59) 



I Main aud connectiug-fibres distinguished. 

 The former contain foreign bodies ; the 

 latter are simple Aplysinopsis, p. 149. 



Main and connecting-fibres distinguished. 

 The latter of two kinds : primaries and 



58 ■( secondaries. The primai'ies form a loose 

 network, the meshes of which are occupied 

 by a reticulation formed by the slender 

 secondaries LuiFaria, p. 151 . 



Main and connecting-fibres not distinguished ; 



skeleton-net uniform Aplysina, p. 152. 



i'ibres simple ; skeleton very rich in sand . . 60 

 (59) < ]\j;ain fibres fascicular, generally without much 



foreign material (61) 



r Surface conulated. Skeleton composed of a 



uniform network of strings of sand-grains. Dysideopsis, p. 155. 



Surface irregular, sometimes honeycombed. 

 Main and connecting-fibres distinguished. 

 I Skeleton very areniferous, sometimes re- 

 placed by large scattered sand-grains, more 

 or less attached to each other by slender 

 fibres Halme, p. 156. 



(61) Surface conulated Stelospongia, p. 163. 



(56) Fibres usually fascicular Hircinia, p. 175. 



Without microsclera and without a hard spi- 



cular rind or fistulse. Megasclera styli . . Stylotella, p. 185. 



(33) -^ Without microsclera ; with a rind and fistulse. 



Megasclera oxystrongyla Rhizochalina, p. 187. 



^ Microsclera present 62 



r Microsclera sigmata. Spongin highly deve- 



j loped Gelliodes, p. 1S9. 



62 ^ 



I Microsclera sigmata. Very little spongin . . Gellius, p. 189. 



L Microsclera trichites Tedania, p. 190. 



With sigmate or rod-shaped microsclera .... 63 



Without sigmata or rods , . (64), p. 248. 



60 ^ 



(34) { 



