Fig. 1. — The entire Medusa, seen in profile, three times the natural size. A deep 

 exumbral coronal furrow separates the upper hemispheroidal half of the umbrella from 

 the lower funnel-shaped half. In the former, only extremely numerous and very delicate 

 radial exumbral ribs are visible, in the latter besides these, there are sixty-four deep 

 radial furrows. On the umbrella margin, thirty-two groups of sucking-cups and tentacles, 

 alternating with thirty-two larger isolated sucking-cups inserted higher up. 



Fig. 2. — Perradial section through the whole Medusa, three times the natural size. 

 A gelatinous cone (uk) projects downwards in the bottom of the gastral cavity from 

 the apex of the gelatinous umbrella (ug). The eight conical adradial oral funnels (to) 

 project inwardly in the oral part of the gastral cavity ; between the funnels we see 

 the fissure-shaped entrances into the eight pair of alternating buccal pouches (bb). 

 The eight sac-shaped genitalia (s) contain wide genital pouches (bs). mw Subumbral 

 circular muscles. cr Badial canals. ce Centripetal canals. cc Circular canals. 

 ts Tentacles with sucking-cups. 



Fig. 3. — The oesophagus, seen from the outside, six times the natural size. The eight 

 radial canals (cr) which open above, pass into the gastral wall as longitudinal gastral 

 grooves (gs) whose outer wall projects, bb Buccal pouches, mo Folds of the circular 

 muscles of the quadrate oral margin, al Oral lobes. 



Fig. 4. — The oesophagus in perradial longitudinal section, six times the natural size. 

 Letters as in figs. 2 and 3. The conical gelatinous cone of the umbrella (uk) projects 

 above into the gastral cavity. Below, alternating with the eight gastral grooves (gs) 

 the eight adradial conical oral funnels (io) opening to the outside into the umbrella 

 cavity, whilst a pair of buccal pouches (bb) open to the inside into the oral cavity 

 below each oral funnel (comp. fig. 5). 



Fig. 5. — Horizontal transverse section through the oesophagus (z) at the height of 

 the line CD (fig. 4), six times the natural size, bb Buccal pouches, gs Gastral 

 grooves, io Oral funnels. 



Fig. 6. — Horizontal transverse section through the oesophagus at the height of the 

 line AB (fig. 4), six times the natural size, g Gastral grooves, uk Gelatinous cone. 



Fig. 7. — Transverse section through the subumbral wall of the circular canal, greatly 

 enlarged, dc Thick, cylindrical endodermal epithelium ; a nucleus in the middle of 

 each cell, zw Endodermal supporting lamella. mw Muscular folds of the sub- 

 umbrella, x Plate of connective tissue below the muscular folds, qw Ectodermal 

 epithelium of the subumbrella. 



Fig. 8. — Transverse section through the thin peripheric part of the gelatinous 

 umbrella, greatly enlarged. e Exumbrella. w Subumbrella. uf Bundle of elastic 

 supporting fibres. 



Figs. 9, 10. — Two tentacles with terminal sucking-cup, greatly enlarged, qt Ecto- 

 derm, mt Muscles, zt Supporting lamella, dt Endodermal axis. 



