RHIZOSTOMvE — CEPIIEA. 



653 



lappets are similar each to each and are rectangular in outline, being separated by very slight 

 indentations which are spanned by a web. Fairly deep grooves extend up the vertical rim 

 ot the exumbrella surface of the bell, between the lappets. 



The arm-disk is as wide as the bell-radius and is i8 mm. thick. The tree parts, upper, 

 of the 8 bifurcated mouth-arms are each about 20 mm. long. At the center of the arm-disk 

 we find 4 to 1 2 or more tapering, somewhat flattened, wart-covered filaments which are about 

 25 mm. long and terminate each in a simple, pointed end. There are also numerous shorter 

 filaments, ranging from about 15 to 5 mm. in length, all near the center of the arm-disk, and 

 many still shorter ones between the numerous frilled mouths of the 8 mouth-arms. 



There are 4 small, oval, subgenital ostia only about 2 mm. wide. The ring-muscles of 

 the subumbrella are entire, but are very weakly developed. The central stomach gives rise 

 to 8 large rhopalar and about 56 (7X8) somewhat narrower radial-canals, all connected 

 one with another by a network of anastomosing vessels. The rhopalar canals proceed straight 

 through this network, giving of! small side branches to the adjacent radial-canals, but the inter- 

 rhopalar canals tend to lose their identity in the network. There is no distinctly differentiated 

 ring-canal. There is a unitary, cruciform, genital cavity opening to the outer world by the 

 4 genital ostia. There are many fairlv large, reddish-brown dots over the outer surface of 

 the arm-disk and reddish-brown streaks around the exumbrella warts. The color of the bell 



Fig. 405. — Cephea octostyla. Drawn by the author, from specimen.s taken by the Albatross at Jolo .'\nchor- 



age, Philippine Islands, in February and March, 1908. 

 A, B, and C, side views of exumbrella, showing variations in development of warts; D, rhopalium seen 



from subumbrella side. 



is faded in formalin, but a color note states that the exumbrella bore numerous small, round, 

 ocherous spots. When the bell is 15 mm. wide there are a few, small, scattered warts near the 

 center of the exumbrella. There are 8 rhopalia set within shallow niches. The bell-margin 

 between the sense-clubs is entire and there are no lappets. There are 8 quite wide rhopalar 

 and 8X3 somewhat narrower inter-rhopalar canals, all set into communication by side branches 

 forming a marginal network. The 4 genital cavities are separate. The 8 bifurcated mouth- 

 arms lack appendages either upon the arm-disk or between the frilled mouths. This young 

 specimen was caught upon the surface under an electric light in Jolo Anchorage, Philippine 

 Islands, on February 13, 1908. 



Cephea octostyla var. coerulescens Maas. 



Netrostoma caruUscens, Maas, 1903, Scyphomedusen der Sihoga Expedition, Monog. 11, p. 35, taf. 5, fign. 37,46; taf. ii,fign. 

 97, 103; taf. 12, fig. 109; 1906, Revue Suisse de Zool., tome 14, p. loi. — Browne, 1905, Fauna and Gcog. Maldive and 

 Laccadive Archipelagoes, vol. 2, p. 967. 



The bell becomes at least 200 mm. wide. There are 8 marginal sense-clubs, each with a 

 terminal entodermal concretion-mass and without an exumbrella sensory pit. No ocelli (?) In 

 other respects the bell resembles that of Cephea octostyla having a central dome which bears 

 about ID wart-like projections. There are 6 to 8 round-edged, marginal lappets in each 

 octant. The 8 mouth-arms are short, massive, laterally compressed, and curved outwards. 



