THE SCYPHOMEDUSAE 75 



as pouches which project on the subumbral surface into the 

 subumbral cavity (Cyanea), or hang freely into the gastric 

 cavity or radial pouches (Rhizostoma). The sexes are separate, 

 except in Chrysaora ; in this genus some individuals are first male, 

 then hermaphrodite, and finally female only, the ova being con- 

 fined to the interradial generative organs, the spermatozoa occur- 

 ring irregularly at any point in the endoderm ; other individuals 

 are unisexual throughout life. 



CLASSIFICATION AND LIST OF GENEEA OF 

 SCYPHOMEDUSAE. 



The chief authority for this classification is Haeckel (6) ; other attempts 

 are to be found in Glaus, Ueber die Classification der Medusen (Arb. Zool. 

 Inst. Wien, vii. 1888), and Vanhoften, Zur System der Scyphomedusen (Zool. 

 Anz. xiv. 1891). 



ORDER 1. Stauromedusae. (For definition, see p. 61.) 



FAMILY 1. TESSERIDAE. Genera Tessera, Hkl. ; Tesserantha, Hkl. ; 

 Depastrella, HkL ; Depastrum, Gosse ; Tesseraria, Hkl. FAMILY 2. 

 LUCERNARIIDAE. Genera Haliclystus, Clark; Lucernaria, 0. F. Mull.; 

 Halicyathus, Clark ; Craterolophus, Clark ; Lucernosa, Antipa. FAMILY 3. 

 CAPRIIDAE. Genus Capria, Antipa. 



ORDER 2. Peromedusae. (For definition, see p. 63.) 



FAMILY 1. PERICOLPIDAE. Genera Pericolpa, Hkl. ; Pericrypta, Hkl. 

 FAMILY 2. PERIPHYLLIDAE. Genera Peripalma, Hkl. ; Periphylla, 

 Steenstr. ; Periphema, Hkl. 



ORDER 3. Cubomedusae. (For definition, see p. 64.) 



FAMILY 1. CHARYBDEIDAE. Genera Procharagma, Hkl.; Pro- 

 charybdis, Hkl. ; Charybdaea, Pe"r. Les. ; Tamoya, F. Mull. FAMILY 2. 

 CHIRODROPIDAE. Genera Chiropsalmus, L. Agass. ; Chirodropus, Hkl. 



ORDER 4. Discomedusae. (For definition, see p. 67.) 

 SUB-ORDER 1. CANXOSTOMAE. 



Definition. The mouth is simple and devoid of arms. The ten- 

 tacles are solid and generally short. 



FAMILY 1. EPHYRIDAE (in many cases probably larval forms). Genera 

 Ephyra, Per. Les. ; Palephyra, Hkl. ; Zonephyra, Hkl. ; Nausicaa, Hkl. ; 

 Xausithoe, Kiill. ; Nauphanta, Hkl. ; Atolla, Hkl. ; Collaspis, Hkl. 

 FAMILY 2. LINERGIDAE. Genera Linerges, Hkl. ; Linantha, Hkl. ; 

 Liniscus, Hkl. ; Linuche, Escli. 



