6S4 MEDUS.B OF THE WORLD. 



Genus PHYLLORHIZA L. Agassiz, 1862. 



Phyllorhiza, AGASSI/, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 158. HAECKEL, 1880, Syst. dcr Medusen, p. 588. VON LEN- 

 DENFELD, 1884, Proc. Linnean Soc. New South Wales, vol. 9, p. 296. VANHOFFEN, 1888, Bibliotheca Zoologica, Bd. I, 

 Heft. 3, p. 41. 



P/iyllorhiza chincnsis L. Agassiz and P. trifolium Haeckel are too imperfectly described 

 to he recognizable, and P. punctata von Lendenfeld, from Australia, is the type species and 

 the only adequately determined form. 



Phyllorhiza chinensis is probably Cephea cephea, and P. trifolium is, according to Haeckel, 

 described from a preserved and mutilated specimen. It has 96 marginal lappets. Exumbrella 

 finely granular. Arms with 3 semicircular, pmnately-branched, separated lappets or wings, 

 with 24 long and numerous, short filaments, the largest being equal to the bell-diameter. Bell 

 75 mm. wide. Japanese Sea. 



GENERIC CHARACTERS. 



Similar to the closely allied Lychnorhtza but the centripetal vessels which arise from the 

 inner side of the ring-canal join with the central stomach, as in Mastigias, instead ot ending 

 blindly as in Lychnorhiza. Also the ring-muscle of the subumbrella is interrupted in the 8 

 principal radii. The canal-system resembles that of Mastigias, but the mouth-arms have 

 no terminal clubs. 



Phyllorhiza punctata von Lendenfeld. 



Ph\llorliiza punclata, VON LENDENFELD, 1884, Zool. Anzeiger, Bd. 7, p. 429 (development). 1884, Proc. Linnean Soc. New 

 South Wales, vol. 9, p. 296, plate 4, I fig.; p. 307, plate 5, figs. 1-4; 1888, Zeit. fur wissen. Zool., Bd. 47, p. 223, taf. 18, 

 fig. 2; taf. 19, fign. 8, 9, n, 12; taf. 21, fign. 17-20, 22; taf. 22, fign. 27-35, taf. 23, fign. 40, 53-55; taf. 26, fign. 79, 

 80, 86; taf. 27, fign. no, 117 (detailed description). MAAS, 1903, Scyphomedusen der Siboga Expedition, Monog. 1 1, p. 60. 



Umbrella somewhat flatter than a hemisphere, 500 mm. wide. Exumbrella 50 mm. 

 thick, with a finely granular surface. 8 marginal sense-organs. In each octant there are 

 2 sickle-shaped ocular lappets, 4 simple lappets near the ocular lappets, and 4 double lappets 

 near the middle of each octant. There are thus 14 lappets in each octant, considering each 

 double-lappet as two. The large, double lappets are partially fused by a basal web, and the 

 ocular lappets are only half as wide as the others and are sharp-pointed, while the others are 

 rounded. Radial furrows extend centnpetally over the exumbrella between the lappets. The 

 arm-disk is thick and a liitle wider than the bell-radius, octagonal in shape and has a canal- 

 system of its own. It is thickly beset with filaments on its ventral side, to which young embryos 

 in the gastrula stage adhere. The 4 subgenital ostia are oval and more than twice as wide as 

 the pillars between them. The eight 3-leaved mouth-arms are two-thirds as long as diameter 

 of umbrella. Their 3 mouth-bearing edges branch pinnately, but the pinnae are only rudi- 

 mentary. The lower parts of the mouth-arms bear numerous, tapering, bluntly-ending fila- 

 ments, some of which are two-thirds as long as the mouth-arms themselves. The circular 

 muscles of the subumbrella are interrupted in the 8 principal radii. 



8 radial-canals, 4 perradial and 4 interradial, arise from the cruciform, central stomach 

 and extend to the 8 marginal sense-clubs. A wide ring-canal, at some distance inward from 

 the margin, connects all 8 radial-canals. On its outer side the ring-canal gives rise to a fine- 

 meshed network of vessels (which fuse also with the radial-canals) extending into the lappet 

 zone. On its inner side the ring-canal also gives off a similar network of vessels which connects 

 with the central stomach and with the 4 interradial, but not with the 4 perradial, canals. 



The arm-disk, main stems, branches of the mouth-arms, and gelatinous substance of 

 the umbrella are colorless. In the gelatinous substance of the umbrella, close to the surface, 

 are groups of unicellular, yellow, plant cells which give the whole surface a brown color. Also 

 in the gelatinous substance, close to the surface of the exumbrella, there are cloud-like masses 

 of minute, highly refractive bodies which give the medusa a spotted appearance, the spots being 

 whitish. The frilled mouths are brown and the filaments colorless. 



This medusa is found in Port Jackson, New South Wales, Australia, and is described 

 in elaborate detail by von Lendenfeld (Zeit. fur wissen. Zool.). He finds that during develop- 

 ment the marginal sense-organs decrease from 24 to 16, and finally to 8. 



When the medusa is 15 mm. wide there are 24 marginal sense-organs and 48 marginal 

 lappets. The 2 ocular lappets of each octant are sharp-pointed, narrow, and elongate, while 



