344 A MONOGRAPH OF THE AUSTRALIAN SPONGES. 



VI. OKDO MONACTIHYAL,^. 



SPONGLE, WITH A SKELETON, CONSISTING OF BIACERATE 

 OR TRUNCATE SPICULES, WHICH MAY COALESCE SLIGHTLY, 

 AND WHICH HAVE ORIGINALLY BEEN FORMED AS FLESH- 

 SPICULES. 



1. FAMILY RENIERID^E. 



Monactihyalse, with biacerate spicules, which tend in some 

 cases to become truncate. 



2. FAMILY SUBERITID^E. 



Monactihyalae, with predominant truncate spicules. 



