18,1 Light: Philippine Scyphomedusan Jellyfishes 37 
Type species, Cotylorhiza pacifica Mayer. 
Cotylorhizoides pacificus (Mayer) emend. 
Cotylorhiza pacifica MAYER, Pub. Carnegie Inst. Washington 212 
(1915) 185. 
Bell deeply dome-shaped, reaching a diameter of 300 milli- 
meters and a depth nearly as great. Exumbrella covered with a 
mosaic of faint diffuse brown due to large numbers of minute 
brown spots, apparently clumps of Zoéchlorelle (unicellular sym- 
biotic alge). In formalin specimens this color fades out en- 
tirely, and in alcohol specimens it remains as a mosaic of frosty 
white. A band extending from the inner ends of the velar clefts 
to about the middle of the velar lappets is a dull blue in some 
living specimens, due to the blue color of the canal network 
of that area. The exumbrella is more or less regularly marked 
by porcelain-white spots which have a characteristic appearance, 
due to their being pear-shaped with the swollen portion sub- 
merged; only the smaller end appears on the surface, where it 
simulates the opening of a gland, being transparent in the center. 
This transparent spot which simulates the opening is surrounded 
by a porcelain-white area, this by a transparent area, this by an 
area of diffuse brown, and this finally by an opaque white zone. 
These spots are about 5 to 10 millimeters apart on the surface, 
have a surface diameter of about 1 millimeter, and are from 2 to 
4 millimeters in diameter at their widest point, which is usually 
internal. Toward the periphery these spots become more ir- 
regular, often larger, and sometimes more numerous. The 
exumbrella is also covered with minute cone-shaped papille. 
Each of the 8 sense organs shows a single, large, brown ocellus 
which fades out in formalin. Above each sense organ is a small, 
but deep, exumbrellar sensory pit. 
The rhopalar canals are large and distinct; the numerous in- 
terocular canals which anastomose freely with each other and 
with the ocular canals are much smaller than the ocular canals. 
The ring canal, while small, can be demonstrated by injection 
or dissection. ; 
There are no radial muscles. The strong circular muscles 
extend to the bases of the mouth-arm pillars and are interrupted 
in the rhopalar areas, completely so internal to the ring canal 
and nearly so external to it. 
The subgenital ostia are about one and a half times as wide as 
the mouth-arm pillars and have a convex lower border. In a spec- 
imen, 200 millimeters in diameter, the mouth-arm disk had a 
diameter of 110 millimeters; the perradial mouth-arm pillars 
were 40 millimeters across, and the subgenital ostia, 60. 
