96 PORIFERA. 



Sub-fam. 1. Renierinae. Spicules may be enveloped by a small pro- 

 portion of spongin, but are never completely enveloped in it. Hcdicliondria 

 Fleming, littoral ; Petrosia Vos. ; Reniera Nardo ; Calyx Vos. 



Sub-fam. 2. Chalininae. Spongin plentiful ; spicules enveloped and 

 united by it. Pachycludina Schm. ; Chalina Grant ; Sipfuniochalina 0. 

 Schm. ; Cacoclialyna 0. S. ; ChalinorrhapMs Lend. ; Hoploclialina Lend. 

 Fam. 2. He terorr aphid ae. Megascleres of various forms ; microscleres com- 

 monly present, but never chelfe. 



Sub-fam. 1. Phloeodictyinae. Sponge massive, with tubular processes 

 (fistulas) projecting from it. With a well-marked external rind. Megasclera 

 oxea, passing into strongyla in some species. Hhizochalina Schmidt ; 

 Oceanapia Norman. 



Sub-fam. 2. Gelliinae. Megascleres all diactinal, oxea, or strongyla. 

 Microsclera as sigmata or toxa ; no rind or fistuhe. Gellius Gray ; Gelliodes 

 Ridley ; Toxochalina Ridley. 



Sub-fam. 3. Tedaniinae. Megascleres of two forms monactinal (styli) 

 forming the main skeleton, diactinal (tylota or tornota) dermal. Micro- 

 sclera as rhaphides. Tedania Gray ; Trachytedania Ridley. 



Sub-fam. 4. Desmacellinse. Megascleres all monactinal, stylote to 

 tylostylote. Microscleres sigmata or toxa, or both. Desmacella Schm.; 

 Biemma Gray. 



Sub-fam. 5. Hamacanthinae. Megascleres oxea or styli. Microscleres 

 large diancistra, and sometimes others. Vomerula Schm.; Hamacantha 

 Gray. 



Fam. 3. Desmacidonidae. Megascleres of various forms, usually monactinal. 

 Microscleres always present and always including chelae. 



Sub-fam. 1. Esperellinae. Skeleton fibre not echinated by laterally 

 projecting spicules. Esperella Vos. ; Espcriopsis Carter ; Cladorhiza M. Sars, 

 megascleres long, often projecting radially, like spines, deep-sea; Axoniderma 

 R. and D. ; Chondrodadia W. Thomson, deep-sea ; Meliiderma R. and D. ; 

 Desmacidon Bow. ; Artemisina Vos. ; Phelloderma R. and D. ; Sideroderma 

 R. and D. ; lophon Gray ; Amphilectus Vos. ; Dcndoryx Gray ; Forcepia 

 Carter ; Yvesia Topsent ; Metonanchora Carter ; Damiria Keller, etc. 



Sub-fam. 2. Ectyoninae. Skeleton fibre echinated by laterally projecting 

 spicules. Myxilla Schmidt ; Pytheas Tops. ; Clathria Schm. ; Rhaphidophlus 

 Ehlers ; Stylostichon Tops. ; Microciona Bow. ; Uymcraphia Bow. ; Plocamia 

 O.S. ; Plumohalichondria Carter; Acarnus Gray; Ecliinoclathria, Carter; 

 Agclas Duch. and Mich. ; Echinodictyum Ridley. 



Fam. .4. Axinellidae. Skeleton typically non-reticulate, consisting of ascend- 

 ing axes of fibres from which arise subsidiary fibres radiating to the cortex. 

 Megasclera chiefly styli, to which oxea or strongyla may be added. Microsclera 

 rarely present, never chelate. Hymeniacidon Bow. ; Phakellia Bow. ; Ciocalypta 

 Bow. ; Acanthella Schm. , Axinella Schm. , generally branched ; Raspailia Nardo, 

 branched, whip-like ; Dendropsis R. and D. ; Thrinacoplwra Ridley ; Dictyo- 

 cylindrus Bow. 



Fam. 5. Spongillidae. Fresh-water sponges. Asexual reproduction by 

 gemmules which are often surrounded by a special kind of spicules called 

 amphidiscs. Spongilla Lamarck ; Ephydatia Lamouroux ; Tubella Carter ; 

 Parmula Carter ; Heteromeyenia Potts ; Lubomirskia Dybowski ; Lessepsia 

 Keller ; Uruguay a Carter ; Potamolcpis Marshall. 



