184 Papers from the Department of Marine Biology. 



The bell is 61 mm. in diameter. There are 22 marginal sense-organs and 

 (5 X 22) 1 10 bluntly rounded, barely perceptible, evenly spaced marginal lappets 

 all similar each to each. The arm-disk is about one-third as wide as the bell- 

 diameter and the mouth-arms are compressed dorso-ventrally and when fully 

 expanded extend slightly beyond the bell-margin, but in their ordinary state 

 of contraction they do not quite reach the bell-margin. The side branches 

 of these mouth-arms are short, but each arm is bifurcated at its outer end, 

 the forked part being about one-third as long as the entire arm. There are 

 about 20 slender, flat, tapering, central arm-disk appendages of various 

 lengths, the longest of which is at the center of the oral side and is about half 

 as long as the bell-radius. There is also a spatula-shaped appendage at the 

 crotch of bifurcation of each mouth-arm. These are somewhat stouter than 

 the central appendages, about half as long as the bell-radius, and with a bluish 

 entoderm. There are numerous, minute, spatulate appendages among the 

 mouth-arms. 



The general color of the bell of the medusa is olive-brown. There are 22 

 large, triangular white spots with forked outer ends near the bell-margin in 

 the radii of the sense-organs, and also (3 X 22) 66 short white streaks near the 

 margin in the radii of the velar lappets. There are 22 interradial, dull bluish 

 streaks in the subumbrella alternating with the rhopalia in position. 



This variety is distinguished by its bifurcated mouth-arms. Its nearest 

 ally appears to be Cassiopea andromeda var. acycloblia Schultze, from Amboina, 

 but it differs in its color pattern, in the absence of a central dome, and in its 

 simple bifurcated mouth-arms, those of the Amboina medusa branching 

 dichotomously. 



Cassiopea andromeda is the common species of the Indian Ocean, Red Sea, 

 and Malay Archipelago, and Kellar records its having wandered into the Suez 

 Canal. It gives rise to numerous local varieties. 



There are evidently a number of other varieties of Cassiopea in the Philip- 

 pines, for Light (1914, Philippine Journal of Science, vol. 9, p. 201) describes 

 Cassiopea polypoides var. culionensis, C. polypoidesf, and C. medusa, nov. sp. 

 The last named is distinguished by its very large mouth-arm appendages which, 

 in a medusa whose bell is 260 mm. in diameter, are 110 mm. long and 7.5 mm. 

 in diameter, being cylindrical near the base and flattened at their outer ends. 

 C. medusa is described from Culion Bay, Culion, Philippine Islands. 



Genus CEPHEA Peron and Lesueur, 1809. 



Cephea, PERON ET LESUEUR, 1809, Annal. du Mus. Hist. Nat., Paris, tome 14, p. 360. 



GENERIC CHARACTERS. 



Rhizostomata dichotoma in which the 8 mouth-arms fork once dichotomously 

 and each fork gives rise to short dichotomous or dendritic branches. Solid, 

 wart-shaped tubercles at the center of the exumbrella. The central stomach 

 gives rise to 8 rhopalar and numerous inter-rhopalar radial-canals, all of which 

 connect with a network of anastomosing vessels in a wide zone near the 

 margin. Rhopalia without ocelli and without sensory pits on the exumbrella. 

 There is no definite ring-canal. Development unknown. 



Cephea octostyla (Forskal). 



Medusa octostyla, FORSKAL, 1775, Descript. Anim. Itin. Orient., p. 106, No. 18, Icon., tab. 29. 

 Cephea octostyla, MAYER, 1910, Medusae of the World, vol. 3, p. 652, fig. 405. 



Many well-preserved specimens of Cephea octostyla were obtained by the 

 United States Fisheries Bureau steamer Albatross at Jolo Anchorage, Philip- 

 pine Islands, tropical Pacific, in February and March 1908, and have been 

 described in Mayer's "Medusae of the World," vol. 3, p. 652. 



