676 EXPLANATION OF THE PLATES. 



Fig. p. Echinodictyum ghmsratum, spicules, x 190. From type 

 specimen, from Thursday Island. 



q. E. cancellatum, spicules, x 190. From specimen figured 

 PL XL. fig. D. 



r. E. eostifcrum, spicules, x 190. From specimen from Port 

 Molle. 



s. Leucopldoeus fenestratus, part of vertical section from type 

 specimen, x 38. 



t. Amplulectus tibieUifer, skeleton acuate and tibella and 

 tricurvate acerate spicules, x 190. I', head of tibiella, 

 and t", equianchorate as seen from front and side, x 370. 

 From type specimen from Torres Straits. 



Plate XLIII. 



Fig. a. AxineUa ecJiidncea. Spicules, x 68. From dry specimen 

 from Thursday Island. 



b. Geodia globostellifera, globostellate, external and internal 



stellate spicules, in tissue below dermal crust, x370. b' . 

 Portion of cortex, showing crust of balls covered by mem- 

 brane containing smaller stellates, and tuft of surface 

 acerate spicules projecting from it, x 68. 



c. Spirastrella decumbens. Spicules, x 190. From type 



specimen from Alert Island. 



d. S. congenera, skeletal spinulate spicules, showing two forms 



of head, x 190. d'. Flesh-spicules, x 370. From type 

 specimen from Thursday Island. 



e. S. vagabunda, skeletal spinulate spicule, X 190. e'. Flesh- 



spicules, x 370. From specimen from Torres Straits. 



/. Hymeniacidon agminata, spicules, x 190. /.' Head of spinu- 

 late spicules, x 370. From type specimen from Port Jackson. 



g. Leucojddceus fenestratus, var. Spicule, x 68. 



h. Suberites epiphytum, vertical section, x 68. 7i', spicule 

 X 68 ; h", head of spicule, chief forms, X 370. From 

 spirit-specimen from Port Curtis. 



