REPORT ON THE DEEP-SEA MEDUSAE. 



151 



germinal layer is divided later into the permanent ectoderm (or the external epithelium 

 of the whole body), and the muscles, &c, produced by it. 



qa 

 qe 



'JO 

 qs 



qt 

 qw 



Exoderma oralo. 

 Exoderma exumbrellse. 

 Exoderma gastrale. 

 Exoderma sexuale (Craspedo- 



tarum). 

 Exoderma tentaculorum. 

 Exoderma subumbrella). 



Oral ectoderm. 



Ectoderm of the exumbrella. 



Gastral ectoderm. 



Sexual epithelium of the Craspe- 



dota. 

 Ectoderm of the tentacles. 

 Ectoderm of the subumbrella. 



Exoderm-Epithel des Mundes. 

 Exoderm-Epithel der Exumbrella. 

 Exoderm-Epithel des Magens. 

 Keim-Epithel der Gesehlechts-Organe 



(der Craspedoten). 

 Epithel der Tentakeln. 

 Exoderm-Epithel der Subumbrella. 



r R. Nervi. Nerves. Nerven. 



AVhilst the peripheric nervous system of the Medusae consists of a diffused plexus, 

 extending far under the ectoderm, and connected with it, a ring of nerves, which is 

 double in the Craspedota and simple in the Acraspeda, with ganglionic swellings at the 

 organs of sense, appears as a central part at the umbrella margin. 



re Circulus nervosus. 



re' Circulus nervosus exumbralis. 



re" Circulus nervosus subumbralis. 



rg Plexus nervosus gastralis. 



ro Nervi sensillares. 



rs Plexus nervosus subumbralis. 



Nerve ring. 



Upper nerve ring. 



Lower nerve ring. 



Nervous plexus of the stomach. 



Nerves of the sense organs. 



Nervenring des Schirmrandes. 

 Dorsaler Nervenring. 

 Ventraler Nervenring. 

 Nerven-Plexus des Magens. 

 Sinnesnerven. 



Nervous plexus of the subumbrella. Nerven-Plexus der Subumbrella. 



s. 



Reproductive Organs. 



Geschlechtsorgane. 



Genitalien. 



Sexualia. 



s Genitalia. 



The reproductive organs of all Medusae consist essentially of reproductive glands 

 or gonads, which are developed in both sexes from the ectoderm in the Craspedota, 

 and from the endoderm in the Acraspeda. 



Geschlechts-offnung. 



Gonaden-Blaschen. 



Hohle der Geschlechtsbeutel. 



Entoderm-Epithel der Gonaden. 



Lappen der Geschlechtsdrusen. 



Eierstocke 



Geschlechtsdrusen. 



Hoden. 



Eier. 



Geschlechtsfalten. 



Geschlechtsbucht. 



Fuleral-Geriiste der Gonaden. 



Exoderm-Epithel der Gonaden. 



Samenfaden. 



