EXPLANATION OF THE PLATES. GG9 



Fig. B. Stelispojigiis impleants. The most symmetrical of three 

 specimens from coral-reef, Port Molle ; dry. Nat. size. 



C. Sipkonocludina bullata. Left-hand half of largest dry speci- 



men from Port Curtis, showing two completed tubes, and 

 behind them (c) the margin of an incomplete one. Reduced 

 two thirds nat. size. 



D. Iteniera testudinaria. Small part of large dry specimen from 



4 fms., Port Denison, showing the lobes and ridges which 

 characterize the surface of the species, lleduccd to two 

 thirds nat. size. 



E. JShigochalina spathvlifera. The type (dry) specimen from 



Thursday Island, 4-5 fms. Reduced to two thirds nat. 

 size. [The lower part overrun by the filiform stolons of a 

 Hydroid Zoophyte.] 



F. Ii. canah's. Dry specimen, one of the types, from Port Dar- 



win, 8-12 fms. [The lower end of the figure shows that one 

 end of the canaliform Sponge has been broken off and the 

 centre of the specimen coated by a calcareous Polyzoon 

 (Celle]?ora).~\ Reduced to two thirds nat. size. 



G. Toxochalina robusta. Terminal branches of a spirit-speci- 



men from Port Jackson ; upper surface, showing vents. 

 Reduced to two thirds nat. size. 



H. Cladochcdina subarmiyera. Part of a specimen in spirit 

 from Warrior Reef, Torres Straits, seen from above, 

 showing vents and short and scanty spines. Nat. size. 



I. Qelliodes fibulata. One of the larger and more ramose 

 specimens, exhibiting several anastomoses of the branches. 

 Dry ; from Thursday Island, 3-5 fms. Reduced to two 

 thirds nat. size. 



J. Pellina muricata. Part of the type specimen, in spirit, from 

 Port Darwin, between tide-marks, showing serial arrange- 

 ment of the hispid cloacal tubes to form a wall-like ridge. 

 Nat. size. 



K. Rhaphidophlus procerus. The largest spirit-specimen from 

 Port Darwin, 7-12 fms. [The basal portion includes a 



