482 A MONOGRAPH OP THE AUSTRALIAN SPONGES, 



mostly branched. The ramification is regular or irregular in as 

 much as in some species all the connecting fibres are of uniform 

 thickness and form a network with very regular meshes by 

 continually anastomising with one another ; or there are radial 

 and tangental connecting fibres distinguished. In that case the 

 tangental fibres are much thicker and extend from one main fibre 

 to the other ; the radial ones 2-8 times as the thin and vertical on 

 the former, extend between the adjacent tangental connecting fibres. 

 Both these kinds of ramification of the skeleton fibre are observed 

 in Euspongia species and also in Hippospongia. The connecting 

 fibres in Cacospongia species are not so much branched as in the 

 other two genera so that the meshes of the network, which they 

 form are larger. 



Sand and other foreign bodies are often found in abundance in 

 the surface. The sub-dermal cavities are not very highly developed. 

 The pore-sieves in some species contain a great many small pores, 

 in others again only one or two larger ones. In some, narrow canals 

 lead from the pores into the large tangental canals, which form the 

 sub-dermal cavity, whei-eas in others the pores open direct into 

 them. 



Internal canal system and the ciliated chambers do not possess 

 any peculiarities. The chambers measure on an average 0'099 — 

 0-013 mm., in diameter. 



Sensitive cells occur in various parts of the sponge. 



In the family Spongidse, Schulze (1) acknowledges six genera, 

 namely Euspongia Bronn, Hippospongia Schulze, Phyllospougia 

 Ehlers, Cacospongia Schmidt, Carteriospongia Hyatt and Stelo- 

 spongia Schmidt. The genera Euspongia, Hippospongia and Caco. 

 spongia belong to our sub-family Sponginse. The other three genera 

 comprise sponges, which belong to the next sub-family namely the 

 Chalinopsinje. 



(1) F. E. Schulze. Ueber den Bau unci die Entwickelung der Spongien, 

 VII. te Mittheilung. Die Familie der Spongidse. Zeitschrift fiir wissen- 

 fichaftliche Zoologie. Band XXXII., Heft 1. 



