ANTHOMEDUS^:. 



HYDROMEDUS/E OR VEILED MEDUS/E. 



Medusae with a velum, or diaphragm, which partially closes the marginal opening of 

 the bell. When ripe the sexual products are found in the ectoderm. 



With a double marginal nerve-ring, one above and one below the velum. 



Without gastric filaments. Development either direct from actinula larvae or through 

 alternation of generations from hydroids. 



Order 1. ANTHOMEDUS/E Haeckel, 1879. 



Hydromedusae with gonads in the ectoderm of the manubrium. Without otocysts. 

 The hydroids are of the Tubularian order. 



Family No. i, CODONID.&. 



Anthomedusae with ring-like gonad encircling the manubrium. Four to six simple, 

 unbranched radial-canals. Simple, unbranched tentacles. 



Subfamily No. i, SARSIANJE. 

 Some or all of the tentacles arise singly, not in clusters, from bell-margin. 



PACHYCORDYLE, Weismann, i8%$ = Parvanernus ( ?), Mayer, I94- 



Degenerate medusae without tentacles, radial or circular canals. Hydroid: Pachy- 

 cordyle Weismann. 



AMALTH^EA, Schmidt, 1854. 



Four rudimentary tentacles, four radial-canals, and a ring-canal. Hydroid: Corymorpha. 



PENNARIA, Oken, 1815; Goldfuss, i%2O = Globiceps, Haeckel, 1879. 

 Similar to Amalthaa, but the hydroid is Pennana. 



TRICHORHIZA, Russell, 1906. 



Medusa resembles Pennaria, but the hydroid is Tnchorhiza. 



STEENSTRUPIA, Forbes, iS^.6 = Eup/i\s(i, Forbes, i$4.% = Eupliysora, Maas, 1905. 



Four radially situated tentacles, one of which is long, the other three short. Bell radially 



symmetrical. Hydroid: Corymorpha. 

 HYBOCODON, L. Agassiz, \%()2 = Hybocodon J t-Amphicodon, Haeckel, 1879. 



One or more well-developed tentacles arise from base of one of the four radial-canals. 

 With rudimentary tentacles at the bases of the three other radial-canals. Bell asym- 

 metrical. Hydroid: H ybocodon Agassiz. 



MICROCAMPANA, Fewkes, 1889. 



With one long and five short tentacles, arising at ends of six radial-canals. 



DlcoDONlUM = Dicodonium + Dincmti, Haeckel, 1879. 



Two well-developed and two rudimentary tentacles. No meridional lines of nettle-cells 



over exumbrella. 

 SARSIA, Lesson, i^^.^ = CoJontutn + Sarsia + S'vnJii'tyon, Haeckel, 1879. 



Four equally developed tentacles with abaxial, ectodermal ocelli. No meridional lines 



of nettle-cells over the exumbrella. Hydroid: Syncoryne. 

 StauriJiosarsia new subgenus. Medusa similar to Sarsia, but the hydroid is Stuundia. 



HYDRICHTHYS, Fewkes, 1888. 



Medusa resembles Sarsia, but there are no ectodermal ocelli upon the tentacle-bulbs. 

 Hydroid: H vJrichthys, Fewkes; commensal or parasitic upon fish. 



EUCODONIUM, Hartlaub, 1907. 



Medusa resembles Sarsia, but stomach is mounted upon a gelatinous peduncle. The 

 four tentacles terminate each in a knob-shaped extremity. 



ECTOPI.EURA, L. Agassiz, 1862 (sens. ampl.). 



With two or four tentacles. Eight meridional lines of nettle-cells over the exumbrella. 

 Hydroid: Ectopleura. 



