584 DR. R, VON LENDENFELD ON THE SYSTEMATIC [DcC. 21, 



2. Familia Sollasellid^, Lendenfeld. 

 Digitate forms with radiating spicule-buudles, and distinct ecto- 

 aud endochonae. 



Sollasella, Lendenfeld. 



3. Familia Spirastrellid^, Ridley and Dendy. 



With spirastrellid flesh-spicules. 



Spirastrella, Ridley ; Raphyrus, Bowerbank ; Papillina, Schmidt; 

 Cheirella, Lendenfeld ; Accos, Gray ; and Suberocorona, Lendenfeld. 

 Coincides with the family Cheirellidse, Lendenfeld. 



4. Familia Suberamatid^, mw. 



With hamate flesh-spicules (sigmata). 

 Suberamata, Lendenfeld. 



5. Familia Suberitid^e, Vosmaer, emend. 



Without flesh-spicules. 



Suberitella, Lendenfeld ; Suberites, Nardo ; Suberopetros, Lenden- 

 feld ; Plectodendron, Lendenfeld ; Polymastia, Bowerbank ; Tricho- 

 stemma, M. Sars ; Tentorium, Vosmaer (Thecaphora, O. Schmidt) ; 

 Stylocordyle, Wyv. Thomson ; Quasillina, Norman ; Cliona, 

 Grant; and Poterion, Schlegel. 



IV. Subordo Oligosilicina, Lendenfeld. 



Without supporting skeleton. Flesh-spicules, when present, 

 anaxon polyactinellid. Chambers small, with narrow outlet. 



1. Familia Chondrillid^, Lendenfeld. 



With polyactinellid flesh-spicules. Comprises the genus Chon- 

 drilla, O. Schmidt. 



2. Familia Chondrosidje, Lendenfeld. 



Without flesh-spicules. Comprises the genus Ghondrosia, Nardo. 



in. Ordo CORNACUSPONGI^, Vosmaer, emend. 



Silicea with soft mesogloea, or mesodermal ground-substance. 

 The supporting skeleton is composed of bundles of monaxonids, 

 which are never tylostyle spicules. The skeleton is strengthened 

 by spongin, which cements the spicules. These may disappear 

 altogether, and the skeleton is then composed of spongin, with 

 or without foreign bodies. Exceptionally, also, this horny skeleton 

 disappears. The ciliated chambers have large outlets. 



I. Subordo Halichondrina, Vosmaer. 

 With siliceous spicules in the supporting skeleton. 



1. Familia Spongillid^, Carter. 



Freshwater sponges with gemmulse. 



Spongilla, Lamarck ; Ephydatia, Lamouroux ; Tubella, Carter ; 



