18,1 Light: Philippine Scyphomedusan Jellyfishes 33 
distinguishable beyond the ring canal, the centripetal system 
consisting of one blind canal between each two radial canals (see 
fig. 2). Subgenital ostia wide and narrow, much wider than the 
base of the mouth-arm pillar. Subgenital porticus unitary. 
Fic. 2. A quadrant of Anomalorhiza shawi gen. et. sp. nov. in subumbrellar view, showing 
canal system, subgenital ostium, ete. X 1. 
Type species, Anomalorhiza shawi sp. nov. 
This new genus differs strikingly from the other genera of 
Rhizostomata dichotoma in the unusual branching of the mouth 
arms, which are dichotomously branched only near the tip, 
the entire outer surface of the arm being quite bare; in the 
presence of a very large, distinct ring canal; in that the in- 
terocular canals are but 8 in number; and in the absence of 
any externally visible musculature. It is most nearly related 
to Cotylorhizoides (see diagnosis below) in that they both have 
terminal clubs on the mouth arms, large subgenital ostia, and 
small exumbrellar sensory pits, but differs from Cotylorhi- 
zoides in the points mentioned above and also more strikingly in 
the thinness and fragility of the bell as contrasted to the stiff 
massive bell of that form. , 
Anomalorhiza shawi sp. nov. Figs. 1 to 3. 
The bell, which in the entirely relaxed, preserved specimen is 
nearly flat and measures about 150 millimeters in diameter, is 
1759483 
