98 PORIFERA. 



Phyllospongia Ehlers ; Leiosella Lendf. ; Euspongia Brown ; E. officinalis 

 L., the fine Turkey or Levant sponge ; Hippospongia F. E. S. ; H. equina. 

 0. S., the horse sponge or common bath sponge. Coscinoderma Carter ; 

 Heteronema Keller. 



Sub-fam. 2. Aplysinae. Skeletal network loose, the axis of the fibres 

 is occupied by a kind of pith. Aplysina Nardo; Luff aria Pol.; Thorect- 

 andra Lendf. ; Thoreeta Lendf. ; Aplysinopsis Lendf. 



Sub-fam. 3. Druinellinae. Ciliated chambers with long special efferent 

 and afferent canals ; fibres thick with irregular lobose surfaces. Druinella 

 Lendf. 



Sub-fam. 4. Halminae. Skeleton as a network of slender fibres containing 

 at the nodes large sand-grains ; or with a skeleton of loose sand-grains and 

 dendritically-branched areniferous fibres. Oligoceras F. E. S.; Dysideopsis 

 Lendf. ; Halme Lendf. 



Sub-fam. 5. Stelosponginae. Skeletal network wide-meshed, composed 

 of solid fibres more or less fasciculated. Stelospongia Schmidt ; Hircinia 

 Nardo. 



Fam. 3. Spongelidae. With large saccular ciliated chambers without efferent 

 canals, a clear ground substance, and a skeleton of solid fibres without 

 proper spicules, but containing sand-grains. Sometimes the fibres are replaced 

 entirely by large scattered sand-grains. More closely allied to the Heteror- 

 r aphides, than to any family of Ceratina. 



Sub-fam. 1. Phoriosponginae. With microscleres. Phoriospongia 

 Marshall ; Sigmatella Lendf. 



Sub-fam. 2. Spongelinae. Without microscleres. Spongelia Nardo; 

 Psammopemma Marshall ; Haastia Lendf. ; Psammoplysilla Keller. 

 The deep-sea Ceratosa of Haeckel (Challenger Reports, vol. xxxii., 1889), 

 belong to this order. He distributes the forms into four families : 



Ammoconidae, without spongin skeleton ; Psamminidae, without spongin 

 skeleton ; the Stannomidae, with spongin skeleton ; and the Spongelidae. Most 

 of them were taken at a depth of from 2000 to 3000 fathoms. 



