A MONOGRAPH OF THE AUSTRALIAN SPONGES. 



(Continued.) 



By R. von Lendenfeld, Ph.D. 



Part III. 



[Plates LIX. to LXVII.] 



PRELIMINARY DESCRIPTION AND CLASSIFICATION 

 OF THE AUSTRALIAN CALCISPONGI^. 



CLASSIS SPONGI.^. 



CGELENTERATA, WITH A GASTRO VASCULAR SYSTEM WHICH 

 OPENS ON THE SURFACE WITH MANY SMALL AND MOSTLY 

 ONE OR A FEW LARGE APERTURES. NOURISHING MATERIAL 

 FLOWS IN THROUGH THE SMALL PORES, THE LARGE PORES 

 OR OSCULAE ARE CLOACA. FRILLED CILIATED CELLS ARE 

 GENERALLY AMASSED IN CERTAIN PORTIONS OF THE CANAL 

 SYSTEM. ALL THE EPITHELIA CONSIST OF SINGLE LAYERS 

 OF CELLS, THE MESODERM IS HIGHLY DEVELOPED. 



L— ORDO CALCISPONGl^. 



SPONGI.E POSSESSING A SKELETON COMPOSED OF CARBO- 

 NATE OF LIME WITH A LITTLE ORGANIC SUBSTANCE, 

 GASTRULA FORMED BY INVAGINATION. 



I.— SUBORDO HOMOCCELA. Von Lendenfeld. 



Calcispongise the Entoderm of which consists throughout of 

 frilled flagellate cells. No histological diflference between the 

 Entodermal clothing of the central gastral cavity and that of its 

 branches. 



