Studies on Sponges. 445 



fam. III. Spongelidae. Ciliated Chambers large, poiich-shaped. 

 Communicatiou of inhalant canals and lacimae with the 

 Chambers by means of numerous pores in the latter. 

 Communication of exhalant canals and lacunae with 

 the Chambers by means of one wide mouth. Fibres 

 anastomosing in order to form a regulär or irregulär 

 network. Axis of fibres thin; main fibres often with 

 sand; groundsubstance without granules. 

 Spongelia^ Velinea. 



fam. IV. Spongidae. Ciliated Chambers small, hemispherical. Com- 

 munication of inhalant canals and lacunae with the 

 Chambers by means of numerous pores in the latter. 

 Communication of exhalant canals and lacunae with 

 the Chambers by means of special wide canals. Fibres 

 anastomosing in order to form an irregulär network. 

 Axis of fibres hardly visible. Main fibres often with 

 sand; groundsubstance in the neighbourhood of the 

 ciliated Chambers with numerous granules. No fila- 

 ments. 

 Euspongia^ Cacospongia^ Phyllospongia , Carteriospongia , Stelo- 

 spoiigia. 



fam. V. Hircinidae. Ciliated Chambers small, hemispherical. Com- 

 munication of inhalant canals with the Chambers by 

 means of numerous pores in the latter. Communicatiou 

 of exhalant canals with the Chambers by means of spe- 

 cial canals. Fibres anastomosing in order to form au 

 irregulär network. Axis of fibres hardly visible. Main 

 fibres always, the other fibres often with sand and 

 other foreign corpuscles. Groundsubstance in the neigh- 

 bourhood of the ciliated Chambers with numerous gra- 

 nules. Between the skeleton-fibres numerous filaments. 

 Hir ernia ^ Oligoceras. 

 The foUowing analytical list may be useful for determination : 



1 a. Skeleton-fibres anastomosing 2 



b. Skeleton-fibres not anastomosing ; tree-like ramified, (or 



sex-radiate) fam. AplysilUdae. 



2 a. No filaments 3 



b. Numerous filaments fam. Hircinidae. 



3 a. Groundsubstance between the ciliated Chambers granular . . 4 



