SCYPHOMEDUSJE RniZOSTOMEJE. 261 



umbrella edge, the number of lobes and marginal tentacles present 

 great variations. 



Fam. Ephyropsidae. Epliryopsi*, Ggbr. (Namithrt Koll). Disc small and 

 like that of Epliyra, vith sbrvple gastric sacs, without oral arms, but with eight 

 marginal tentacles. The genital organs (in four pairs) do not lie in umbrella 

 cavities. E. iwlagica Koll., Mediterranean and Adriatic. 



Fam. Pelagidtf. Pelagia Per. Les. With wide gastric pouches and eight 

 long marginal tentacles in the interradii. No alternation of generations. P. 

 noctiluca Per. Les., Mediterranean. Clirysaora Per. Les., with twenty -four 

 long marginal tentacles. The radial and intermediate gastric pouches are per- 

 ceptibly different. Clir. liysoscclla Esch. Hermaphrodite, North Sea and 

 Adriatic. 



Fam. Cyaneidae. Cyanea P6r. Les. The tentacles are united in bundles on 

 the under surface of the deeply lobed thick disc. There are sixteen (eight 

 radial and eight intermediate) more or less wide gastric pouches, which break 

 up near the end of the marginal lobes into small ramified vessels. C. capillata 

 Esch. 



Fam. Aurelidoe. Discomedusa Cls. With large oral arms, with branched 

 vessels and 24 marginal tentacles. Subgenital pits present. D. lobata Cls., 

 Adriatic. Aurelia Per. Les., with branched radial vessels and edge of disc 

 fringed with small tentacles. A. aurita L. (Medusa, aurita L.), Baltic, North 

 Sea, Adriatic, etc. A.flavidula Ag., coast of North America. 



2. Rhizostomece. No central mouth, funnel-shaped slits in tho 

 eight oral arms and eight, rarely twelve, marginal bodies on the lobed 

 margin of the disc. There are no marginal tentacles. The central 

 mouth, which is at first present, becomes closed during the larval 

 development by the fusion of the edges of the lips. Funnel-like splits 

 are formed on the folded edges of the four pairs of arms, the so- 

 called suctorial mouths, by means of which microscopic bodies are 

 received into the canal system of the oral arms (fig. 195). 



Rliizostoma Cuv. The arms end in simple tubular prolongations, and bear 

 accessory tufts at their bases. RJi. Cuvieri Per. Les., Ceplie-a Per. Les. The 

 branched oral arms have groups of nematocysts and long filaments between 

 the terminal tufts. Cepliea Per. Les. (C'assiopca) borbonica Delle Ch., Medi- 

 terranean and Adriatic. 



CLASS III. CTENOPHORA.* 



Medusce of spherical or cylindrical, rarely band-shaped form / with 

 eight meridional rows of vibratile plates formed of fused cilia. They 



* C. Gegenbaur, "Stuclien iiber Organisation und Systematik der Cteno- 

 phorcn." Archiv. fur Naturyesch., 1856. L. Agassiz, " Contributions to the 

 Natural History of the United States of America," vol. iii., Boston, 1860. 

 A. Kowalevski, "Entwickelungsgeschichte der Rippenquallen." Petersburg, 1866. 

 H. Fol, " Ein Beitrag zur Anatomie und Entwicklungsgeschichte einiger Rip- 

 penquallen," Inaugural dissertation. Jena, 1869. A. Agassiz, " Embryology 

 of the Ctenophor," Cambridge, U.S., 1874. C. Chun, "Die ^tenonhoren de's 

 Golt'cs von Neapel," Leipzig. 1880. 



