RHIZOSTOM.E — PSEUDORHIZA. 683 



mouth aloni^ the lower side of the 8 mouth-arms. These arms are 3-leaved and tlie free edges 

 of these leaf-hke expansions branch profuscI\- and complexly The 8 club-shaped axial appen- 

 dages which arise from the lower ends of the 8 arms are each about as long as the diameter of 

 the disk. 



The 4 subgenital ostia are somewhat wider than the supports between them. There 

 is a single subgenital cavity. The cruciform, central stomach gives rise to 16 radiating 

 canals, 8 to the sense-organs and 8 to the intermediate positions. These 16 canals are put 

 into connection one with another by a ring-canal. On the outer side of this ring-canal is an 

 anastomozing network of vessels, and extending inward from the ring-canal are 160 blindly- 

 ending, centripetal vessels, 10 between each pair of adjacent radial-canals. 



Umbrella colorless, the valleys of the reticulate elevations of the exumbrella violet. The 

 entoderm of gastrovascular cavity brown. Upper parrs of mouth-arm grooves rose-colored. 

 Arms colorless and transparent. Mouth-frills along the margins of the grooves and distal 

 ends of the long axial mouth-arm clubs rich violet. 



Found at Port Philip, Victoria, and at Adelaide, South Australia. 



Described in detail by von Lendenfeld, in Zeit. wissen. Zool. It differs from Haacke's 

 " Monorhiza" in that there are 8 moderately long, mouth-arm filaments, instead of only one 

 verv long filament, and the centripetal canals anastomose into a network on the inner side 

 of the ring-canal instead ot remaining separate, as in Haacke's medusa. 



Pseudorhiza haeckelii Haacke. 



Pseii/lorhiza haeckelii, H:\acke, 1884, Biol. Centralbl., BJ. 4, p. 291. 



Monorhiza haeckelii, Haacke, 1887, Jena. Zeit. fUr Naturwissen, BJ. 20, p. 614, taf. 37, fign. 1-9. 



Disk hemispherical to hat-shaped, 200 to 250 mm. wide and 50 to 100 mm. high. 

 Exumbrella roughened with polygonal, wart-like reticulations. 4 elongate, wart-like pro- 

 tuberances upon the subumbrella in the 4 interradii beyond the 4 subgenital ostia. 8 marginal 

 sense-organs flanked by 16 short, narrow, sharp-pointed lappets. The 48 velar lappets are 

 wide, short, and rounded. There are thus 8 marginal sense-organs and 64 lappets. The 

 central mouth opening is 4-cornered, and the central disk gives rise to 4 pairs of laterally 

 compressed 3-leaved mouth-arms. Each leaf of these mouth-arms gives rise to many flat, 

 fern-like expansions. A single filament, 300 mm. long, arises from the lower end of one 

 of the mouth-arms; it is spindle-shaped and 3-cornered in cross-section. The 4 subgeni- 

 tal ostia are wider than the gelatinous columns between them. The central stomach is 

 Maltese-cross-shaped and gives rise to 16 canals, 8 extending outward in the radii of the 

 marginal sense-organs, and 8 being adradial. These 8 ocular canals extend outward to the 

 rhopalia, but the adradial canals end in the ring-canal near the middle zone of the subumbrella. 

 This ring-canal gives rise in each octant to about 18 narrow, unbranched, non-anastomosing, 

 centripetal canals which end blindly. On the outer side of the ring-canal is a network ot 

 anastomosing vessels which fuse with the 8 rhopalar radial-canals. The circular muscles of 

 the subumbrella are well-developed over the peripheral half of the under side ot the bell and 

 are only partially interrupted in the 8 principal radii. 



The gonads form 4 U-shaped walls of the subgenital ponicus and are much folded. The 

 gastric filaments are so inconspicuous that Haacke failed to find them, although according to 

 von Lendenfeld they are present. Like Chrysaora, Pseudorhiza haeckelii is hermaphroditic, 

 for in addition to the central gonads there are sporadic spermaries situated in root-like ento- 

 dermal filaments in the "gutters" or food crevices of the mouth-arms. 



The furrowed network of the exumbrella is violet-brown and the entoderm of the gutters 

 of the mouth-arms dark-red. The large filament glistens in metallic copper-color, and in 

 young specimens it is blue-violet at the base, with a dark-colored, blue and red, spiral, ento- 

 dermal band of color extending throughout its central cavity. The peripheral canal-system 

 of the subumbrella is brownish-red. 



Found in the Gulf of St. Vincent, South Australia, and described in detail by Haacke, 

 1887. Von Lendenfeld regards this medusa as being identical with, or only a variety of, his 

 Pseudorhiza aurosa. 



