REPORT ON THE DEEP-SEA MEDUSA. 



XXI 



special subfamily of the Euphysidse. In it, of the four perradial tentacles, three are 

 rudimentary and transformed into marginal ocelli ; the fourth tentacle only is developed, 

 and therefore so much the more strongly. It is simple in Euphysa and Steenstrv/pia 

 (System, taf. ii. figs. 8-14), but split into two to three filaments in Amphicodon (System, 

 taf. i. figs. 7-9) ; whilst in the former the fundamental form of the umbrella is only altered 

 a little, in the latter (as also in Ilybocodon) it is considerably transformed symmetrically, 



Fig. B. Cannorhiza connem (Discomedusffi, Versurids;). 



Subumbral view of the umbrella. The arm disk with the eight oral arms is removed as the four per- 

 radial arm pillars (ab), which connect the umbrella disk and the arm disk, are cut through, (oi) 

 Inter sense clubs, (nm) Umbrella margin (turned over inwards), (s) Genitalia, (ira) Gelatinous 

 cross of the gastrogenital membrane, (gg), (gh) Peripheric limbs of the gelatinous cross, (ug) 

 Peripheric umbrella corona, (cc) Coronal canal, (cd) Pillar canals, (ca) Adradial canals, (ci) 

 Interradial canals, (ep) Perradial canals. 



and distinctly dipleuric or zeugite. The whole umbrella is here bilaterally compressed 

 and divided by a sagittal plane (in which the curved gastral axis lies) into two sym- 

 metrical equal halves, a right and a left. The lateral transverse axis is equipolar and 

 shorter than the polar sagittal transverse axis, which has often a tentacle at the one 

 pole, and often has Medusae buds at its base. The further the tentacle and its group 

 of buds extends up the umbrella at this point, the more distinct the zeugite form becomes. 



