Fig. 8. — View of the cesophagus from below, six times the natural size, ar Inter- 

 radial furrows of the cesophagus. al Perradial bordering oral lobes, gw Subumbral 

 gastral wall. 



Fig. 9. — Isolated sense cells from the dorsal nerve ring, in connection with two 

 multipolar ganglion cells, about 1000 times the natural size. 



o' 



Fig. 10. — Ganglion cells and nerve fibres from the auditory ganglion (fig. 3, og), 

 about 1000 times the natural size. 



Fig. 11. — The entire Medusa halved by a perradial meridian section, five times the 

 natural size, ug Gelatinous substance of the umbrella, e Exumbrella. ec Coronal 

 furrow of the exumbrella. en Peronia. em Peronial plates, nc Urticating ring of the 

 umbrella margin, ok Auditory clubs, v Velum, w Subumbrella. mw Circular muscle 

 of the subumbrella. h Umbrella cavity, tr Tentacle roots, t Tentacles, cm Marginal 

 canal, ck Peronial canals, bs Internemal gastral pouches (testes), go Central 

 stomach : gu its umbral wall (cover of the stomach) ; gw its subumbral wall (bottom 

 of the stomach), at (Esophagus, al Oral lobes. 



Fig. 12. — Horizontal transverse section through a peronium and the adjacent parts of 

 the umbrella, 400 times the natural size, qw Ectodermal epithelium of the subuinbrella : 

 mw its muscular layer ; zw its supporting plate, ck Lumen of the peronial canals 

 (in transverse section) : dw high vacuolised cylindrical epithelium of their subumbral 

 endoderm ; dn flat, small dice-epithelium of their umbral endoderm. ug Gelatinous 

 substance of the umbrella, uf Elastic fibres of the gelatinous substance, en Urticating 

 skeletal tissues of the peronium (the urticating thread, whose spiral windings have the 

 appearance of fine transverse streaks, has fallen out of many of the transected thick-walled 

 nematocysts). ml Longitudinal muscular fibres on the axial side of the peronium, in 

 transverse section, zp Supporting lamella of the peronium. en Peronial plate (embedded 

 double lamella of the ectodermal epithelium, comp. PI. XIII. fig. 7). 



