132 THE VOYAGE OF H.M.S. CHALLENGER. 



rhopalar, marginal selvage, are likewise without dendritic side branches. Anastomosed 

 formation between adjacent branch canals never takes place, and there is no trace of a 

 coronal canal (fig. 1, quadrant to the right above). 



The genitalia or reproductive glands (PL XXXI. figs. 9-11) comport themselves the 

 same as in Oyanea and Desmonema. They form four long band-shaped frills, which are 

 fastened to the endodermal inner wall of four powerful, many-folded, gastrogenital 

 pouches. The latter are four interradial csecal sacs of the central stomach, which project 

 as evaginations of the bottom of the stomach between the four perradial oral pillars and 

 hang down as wide, thin-walled sacs, which are nearly half as long as the radius of the 

 umbrella (figs. 1, 8, 9, gg). They alternate with the four perradial arm curtains, which 

 are twice the length, and like them, consist of an extremely delicate, thin-walled, trans- 

 parent membrane. This gastrogenital membrane lies, like the arm curtains, in numerous 

 longitudinal folds, as the peripheric csecum of the gastrogenital pouches is of far larger 

 extent then its narrow base of insertion. The long, narrow, genital band (fig. 10, s) lies 

 at the bottom of the caecum, fastened to its endodermal inner surface. The genital band 

 is laid together in numerous windings, and folded thickly like a frill. The numerous, 

 short, gastral filaments are spread not far from its proximal margin on the inner surface 

 of the gastrogenital pouch (fig. l\,f). Stronger magnifying power shows us that each 

 fold of the frill is composed of a very large number of small follicles (fig. 11, sb). The 

 hollow spaces of these follicles, or the genital sinus, open into the gastrogenital pouch. 

 The ripe sexual products fall first into the pouch, from which they pass into the stomach, 

 and are finally emptied out through the mouth. They probably reach the exterior as in 

 Oyanea, through the arm furrows in the folds of arm curtains, which shelter the fructified 

 ova for some time, like a protective breeding pouch. 



Third Sub-okdek of the Discomedus^e, EHIZOSTOMiE, Cuvier, 1799. 



Root-mouthed Discomedusse. Discomedusse with eight large, adradial, root-shaped, 

 simple or branched oral arms, with numerous mouths of the funnel frills, without central 

 oral opening and without tentacles. 



Family, Crambessid.e, Hseckel, 1869. 



Crambessim:, Hieckel, System der Medusen, 1879, p. 614, taf. xxxviii., xxxix. 



Rhizostompe with a single, central, sub-genital porticus, and with both dorsal and 

 ventral funnel frills of the eight oral arms. Discomedusse without tentacles and without 

 central oral opening ; in place of it numerous small funnel openings form funnel frills 

 both on ventral (axial) and on the dorsal (abaxial) sides of the eight oral arms. Eight 

 sense clubs (four perradial and four interradial) ; eight to sixteen or more narrow radial 

 canals, which are branched and by anastomosis form a vascular network in the sub- 



