Fig. 1. — Ventral view of the entire Medusa (from below), four times the natural size 

 gc Central part of the flat gastral cavity, am Oral margin, swollen and thickened, gw 

 Subumbral wall of the central gastral cavity, sf Ring-shaped genitalium (ovary), h 

 Umbrella cavity (peripheric part), v Velum. I Collar lobes, ok Auditory clubs. 

 t Tentacles. 



Fig. 2. — Profile view of the entire Medusa (from the side), three times the natural size, 

 drawn from life. The central gelatinous umbrella lens touches the expanse of water and 

 the knee of the genuflected tentacles with its vaulted arch. The tentacles are inserted in 

 the circular coronal furrow, which separates the central umbrella lens from the peripheric 

 umbrella collar and alternates with the twenty-five collar lobes of the latter. 



Fig. 3. — Eadial section through the umbrella, six times the natural size. ug 

 Gelatinous lens of the umbrella. ec Coronal furrow of the exumbrella. t Tentacle. 

 tr Tentacle root. I Collar lobes. hi Cavities of the collar lobes, oo Peronium. 

 oh Auditory club, cf Festoon canal. nc Urticating ring. v Velum, sf Ovary. 

 gc Central stomach, at OEsophagus. am Margin of the mouth, h Umbrella cavity. 



Fig. 4. — Tangential transverse section through the ovary, greatly enlarged, dg 

 Endodermal epithelium of the subumbral gastral wall. z Supporting plate (fulcral 

 lamella), qs Ectodermal germinal cells (young ova), so Mature ova cells, qg Ecto- 

 dermal epithelium of the subumbrella. 



Fig. 5. — Longitudinal section through the oesophagus, greatly enlarged, dg High 

 C3dindrical epithelial cells of the endoderm. gd Flask-shaped glandular cells between 

 the epithelial cells. zg Thick supporting lamella, mg, Longitudinal muscles, mg, 

 Transverse muscles, qg Flat epithelial cells of the ectoderm. 



Fig. 6. — Two collar lobes, with the surrounding parts seen from the outside, ten times 

 the natural size, t TeDtacles. tr Tentacle roots, n Urticatino; swelling at the bars of the 

 tentacle roots, cf Festoon canal, nc Urticating ring of the umbrella margin. 

 oo Otoporpse. oh Auditory clubs, v Velum. 



Fig. 7. — A tentacle root, greatly enlarged and foreshortened. We see clearly the 

 branched streams of protoplasm running from its nuclear layer to its mural layer. 



Fig. 8. — A small piece of the umbrella margin, with an auditory club (oh) and its 

 otoporpaa (oo) ; greatly enlarged, n Spheroidal nematocysts. % Supporting lamella, 

 / Gelatinous substance of the umbrella collar, cf Festoon canal, nc Urticating ring. 

 oh Auditory hairs, ot Otolites, v Velum. 



