THE HYDROMEDUSAE 55 



Allm. [?} FAMILY 10. PLUMULARIIDAE (gonophores probably sessile 

 throughout). Genera Plumularia, Lamk. pars. ; Antennularia, 

 Lamk. ; Acanthellci, Allm. ; Schizotricha, Allm. ; Sciurella, Allm. ; 

 Polyplumaria, G. O. Sars ; Heteroplon, Allm. ; Nemertesia. FAMILY 11. 

 CALICARPIDAE. Genera Calicarpa [?] ; Hippurella, Allm. [?]. FAMILY 1 2. 

 HYDROCERATINIDAE. Genus Clathrozoon, Spencer [?]. INCERTAE SEDIS 

 Tricky dra, S. Wright [?] ; Coppinia, Hassall [?]. 



ORDER 3. Trachomedusae. (For definition, see p. 30.) 



FAMILY 1. PETASIDAE. Genera Petasus, Hkl. ; Dipetasus, Hkl. ; 

 Petasata, Hkl. ; Petachnum, Hkl. ; Aglauropsis, F. Mull. ; Gossea, L. Agass. ; 

 Olindias, F. Miill. FAMILY 2. TRACHYNEMIDAE. Genera Trachynema, 

 Gegenb. ; Marmanema, HkL ; Rhopalonema, Gegenb. ; Pectyllis, Hkl. ; 

 Pectis, Hkl. ; Pectanthis, Hkl. ; Homoeonema, Maas. ; (?) Pantachogon, Maas. 

 FAMILY 3. AGLAURIDAE. Genera Aylantha, Hkl. ; Aglaura, Pe"r. Les. ; 

 Agliscra, Hkl. ; Stauraglaura, Hkl. ; Persa, M'Crady. FAMILY 4. GERY- 

 ONIDAE. Genera Liriantha, HkL, = Liriope, Less. ; Glossoconus, Hkl. ; 

 Glossocodon, HkL ; Geryones, Hkl. ; Geryonia, Per. Les. ; Carmaris, HkL ; 

 Carmarina, Hkl. 



ORDER 4. Narcomedusae. (For definition, see p. 33.) 



FAMILY!. CUNANTHIDAE. Genera Cunantha, Hkl. ; Cunarcha, Hkl. ; 

 Cunoctantha, Hkl. ; Cunoctona, Hkl. ; Cunina, Esch. ; Cunissa, Hkl. 

 FAMILY 2. PEGANTHIDAE. Genera Polycolpa, Hkl. ; Polyxenia, Esch. ; 

 Pegasia, P^r. Les. ; Pegantha, Hkl. FAMILY 3. AEGINIDAE. Genera 

 Aegina, Esch. ; Aeginella, Hkl. ; Aegineta, Gegenb. ; Aeginopsis, Brandt ; 

 Aeginura, Hkl. ; Aeginodiscus, Hkl. ; Aeginodorus, HkL ; Aeginorhodus, 

 Hkl. FAMILY 4. SOLMARIDAE. Genera Solmissus, Hkl. ; Solmundus, 

 Hkl. ; Solmundella, Hkl. ; Solmoneta, HkL ; Solmaris, Hkl. 



ORDER 5. Hydrocorallinae. (For definition, see p. 35.) 



FAMILY 1. MILLEPORIDAE. Genus Millepora, Linn. FAMILY 2. 

 STYLASTERIDAE. Genera Sporadopora, Moseley ; Pliobothrus, Pourtal. ; 

 Errina, Gray ; Distichopora, Lamk. ; Labiopora, Moseley ; Spinipora, 

 Moseley ; Allopora, Ehrenb. ; Stylaster, Gray ; Stenohelia, S. Kent ; 

 Conopora, Moseley ; Cryptohelia, M. E. and H. ; Astylus, Moseley. 



ORDER 6. Siphonophora. (For definition, see p. 38.) 

 SUB-ORDER 1. DISCONECTAE. 



Definition. Siphonophora with an apical chambered pneumatophore, 

 without nectophores or bracts. The individuals are confined to the lower 

 surface of the pneumatophore, and are a single central gastrozooid, 

 surrounded by concentric girdles of blastostyles and dactylozooids. 



FAMILY 1. DISCALIDAE. Genera Discalia, HkL ; Disconalia, Hkl. 



