12 MEDUS.E OF THE WORLD. 



Family No. 3, ^EQUORIDjE. 



Leptomedusae with otocysts, and with eight or more radial-canals. 



OCTOCANNA, Haeckel, 1879. 



Eight radial-canals, 45 apart. Eight lips. No ocelli. (Is this a young jEquorea ?) 



OCTOGONADE, Zoja, 1896. 



Similar to Octocanna, but the marginal sense-organs have ocelli as well as lithocysts. 



STOMOBRACHIUM, Brandt, lS^^ = Stomobrachium + Staurobrac/iium, Haeckel, 1879. 



Eight or more simple, unbranched radial-canals, which arise at equal intervals from the 

 margin of the stomach. Four lips. 



HALOPSIS, A. Agassiz, 1863, 1865. 



Radial-canals arise in four groups from the four perradial corners of stomach. Four lips. 



^EQUOREA, Peron and Lesueur, i$og = &(juorea + R/iegmatoJes + Mesonema 



-\-Polycanna, Haeckel, 1879. 



More than eight simple, unbranched radial-canals which arise separately from the mar- 

 gin of the stomach. More than four lips. Subumbrella smooth, without gelatinous 

 papilla-like protuberances. Hydroid: Campanulina. 



ZYGODACTYLA, Brandt, 1835; sensu Agassiz, 1862. 



Similar to jEquorea, but with interradial rows of papilla-like, gelatinous protuberances 

 upon the subumbrella. 



, Haeckel, 1879. 



With bifurcated or branched radial-canals which arise at equal intervals from the margin 

 of the stomach. More than four lips. No peduncle. 



ZYGOCANNULA, Haeckel, 1879. 



Similar to Zygocanna, but the stomach is mounted upon a gelatinous peduncle. 



Order No. 3. TRACHYMEDUS.E Haeckel, 1866. 



Medusae with a marginal velum, and with lithocyst concretions of entodermal origin. 

 With simple uncleft bell-margin. 



Family No. i, OLINDIADJE. 



Some or all of the tentacles project from the sides of the bell, above the margin, and have 

 adhesive disks. Gonads linear, sac-like, or folded, and developed upon the four or six radial- 

 canals. The tentacles arise separately and are not grouped in clusters. 



GONIONEMUS, A. Agassiz, 1862, 1865. 



All of the tentacles project from sides of bell in a zone slightly above bell-margin. All 

 have adhesive disks. Four radial-canals. Lithocysts external, on bell-margin. No 

 centripetal canals. Development through an attached hydra stage. (Perkins.) 



CUBAIA, Mayer, 1894. 



Similar to Gonionemus, but with two sets of tentacles, one arising from the bell-margin 

 and the other set projecting from the sides of the bell, as in Gonionemus. 



VALLENTINIA, Browne, 1902. 



Similar to Cubaia, but with lithocysts inclosed within the gelatinous substance of the 

 bell, adjacent to the ring-canal, and on the inner side above the velum. (Is this 

 a young Olindias]) 



OLINDIAS, F. Miiller, 1861. 



Similar to / allentmia, but with blindly-ending, centripetal diverticula from the ring-canal. 



