The meaning of the letters is the same in all the figures. 



aa Mouth. 



al Oral lobes (perradial). 



as Oral cross (perradial). 



be Coronal pouches. 



bl Lobe pouches. 



bo Ocular pouches (principal coronal pouches, 



four perradial and four interradial). 



br Radial pouches. 



bt Tentacular pouches (adradial coronal 



pouches). 



cs Coronal sinus. 



ds Endodermal germinal epithelium. 



dw Endoderm of the subumbrella. 



cc Coronal furrow of the exumbrella. 



es Eadial furrows of the umbrella disk. 



/ Gastral filaments. 



ga Buccal stomach. 



gb Basal stomach. 



gc Central stomach. 



gi Valves of the pylorus. 



go Gastral ostia. 



gp Palatine opening. 



gy Pyloric opening. 



gw Subumbral wall of the stomach. 



h Umbrella cavity. 



i Interradial funnel cavities. 



hi Subradial septa (fused clasps). 



hi Interradial septa (cathammal nodes or 



fused nodes). 

 / Subradial marginal lobes. 

 Ip Selvedge of the marginal lobes (patagium). 

 mc Coronal muscle. 



Proximal margin of the coronal muscle. 



Distal margin of the coronal muscle. 



Perradial deltoid muscles. 

 md" Interradial deltoid muscles. 

 o Sense clubs. 

 q Ectoderm. 



s' Free proximal part of the genitalia. 

 s" Veiled distal part (covered by the coronal 

 muscle) of the genitalia. 



Follicle of the testis. 



md' 



sb 

 so 

 ss 



St 

 St' 



t 



ua 



uc 



u>9 



ui 

 up 

 w 



Egg cells. 



Genital sinus. 



Sterigma (genital fulcral framework). 



Eoot of the sterigma. 



Tentacles. 



Adradial pedalia (of the tentacles). 



Central disk of the umbrella. 



Gelatinous substance of the umbrella. 



Interradial ocular pedalia. 



Perradial ocular pedalia. 



Subumbrella. 



Supporting plate (fulcral lamella). 



Fig. 12. — The entire Medusa from below, spread out flat (subumbral view), eight times the 

 natural size. 



Fig. 13. — The entire Medusa, from the side (profile view), eight times the natural size (comp. fig. 1, 

 PL XXVIL). 



Fig. 14. — Interradial section through the entire Medusa, eight times the natural size. 



Fig. 15. — Adradial section through an octant, twenty-five times the natural size, to show the 

 sterigma (st) of the ovaries and the origin of its root (sf) from the umbrella. The genital sinus 

 (ss) is lined by endodermal germinal epithelium (ds). The pyloric valves (gi) with the gastral 

 filaments (/) are visible above at the pyloric opening. 



Fig. 16. — Eadial section through an ovarial fold, greatly enlarged, to show the cylindrical germinal 

 epithelium of the endoderm (ds) which produces the egg cells (so) and lines the genital sinus (ss). 



Fig. 17. — A testis, sixteen times the natural size, to show the composition of the follicles of the 

 testis, which are enclosed by a spacious genital sinus (ss). 



Fig. 18. — A pyloric valve, along witli the phacellus placed on it, which is formed by a bow- 

 shaped series of gastral filaments. 



Fig. 19. — An octant, with granulated polyhedric facets, greatly enlarged. 



Fig. 20. — A sense club from the inner axial side, greatly enlarged, oc Eye (with lens ?)• ok 

 Auditory club, ol Otolite. on Auditory niche, op Pigment pad with tactile plate (op'), os Pro- 

 tective scale (auditory fold), os' Free inverted margin of the protective scale. 



