RHIZOSTOM.E — CEPHEA. 657 



umbrella. 8 of these canals lead to the rhopalia and 3 are in each inter-ihopalar octant, instead 

 of 7 as in C. ca-rulca. There is a wide zone of anastomosing vessels near the margin. The 

 central stomach also sends 8 canals downward into the arm-disk and this in turn to the 8 

 mouth-arms. 



General color of medusa blue, as in ('.. ,a-nil,-<i. The bare apex of the central dome is 

 streaked longitudinally with blue, and a deep blue entodermal band of colorextends aiound 

 the sides of the arm-disk above the subgenital ostia. This blue band is especially wide in 

 the adradii above the bases of the 8 mouth-arms. The unbranched portions of the radial- 

 canals adjacent to the stomach and the canals of the arm-disk and arms are blue. The 

 broad network of anastomosing vessels near the bell-margin is dull coffee-colored and the 

 frilled mouths are of a deeper hue of the same color. 



A large swarm of these medusns was found upon the surface ofl" Vanua Mbalavu Island, 

 Fi)i Islands, on November 25, 1897. 



Cephea cephea var. coerulea Vanhoffen. 



Cephea cterulea, Vanhokken, 1902, Wissen. Ergeb. deutsch. Tiefsee Exped. Valdivia, Bd. 3, Lfg. I, p. 45, taf. 4, fign. 13, 14. 



Bell 57 mm. wide. A dome-like apex 14 mm. wide at the center of the exumbrella is 

 surrounded by an annular furrow q mm. wide. The dome itself bears 6 large and about 30 

 small, rounded, wart-like protuberances, the largest of which are 2.4 to 5 mm. wide; numerous 

 fine punctations between the warts. There are 8 rhopalia. No marginal lappets, but 8 radial 

 thickenings of the gelatinous substance at the margin in each octant. The 4 subgenital ostia 

 are very small. The dichotomous mouth-arms are each 16 mm. long and bear frilled mouths 

 on their ventral sides. There are 4 long filaments at the point of bifurcation of each of the 

 4 primary arm-canals, 16 in all; of these, the second and third are 2 to 3 times longer and 

 much stouter than the first and fourth. Numerous very small filaments are among the mouths. 

 The central stomach gives rise to 64 radial-canals, which break up into a wide, anastomosing 

 network zone near the bell-margin. There are 8 rhopalar radial-canals and 7 inter-rhopalar 

 canals in each octant thus differing from C. ilumoknroa, wherein there are only 3 radial-canals 

 in each inter-rhopalar sector. There is a broad, marginal annulus of ring-muscles in the 

 subumbrella, and centripetal to this is a wide zone of radial-muscles extending from the 

 supports of the arm-disk to the zone of ring-muscles. 



The disk, arms, and filaments are blue and the frilled-mouths are chocolate-brown. 



Found at Dar es Salaam, east coast of Africa (see fig. 408). 



Cephea cephea var. setouchiana. 



Microstylus selouchianuSy Kishinouye, 1902, Journ.il College Sci. Tokyo, vol. 17, Art. 7, p. 11, plates I, 2, figs. 8-10. 

 Netrostoma setouchianus, Browne, 1905, Fauna and Geog. Maldive and Laccadive Archipelagoes, vol. 2, p. 967. 



Disk 100 to 200 mm. wide with a prominent central dome nearly as wide as bell-radius 

 and covered completely by 50 or more solid, pointed, wart-like projections of various sizes. 

 This central dome is surrounded by a wide, annular furrow which separates it from the thin, 

 flexible, outer zone of the exumbrella. 8 rhopalia. 6 to 8 flatly rounded, velar lappets flanked 

 by 2 smaller, rounded, rhopalar lappets in each octant. 50 to 60 lappets, in all, upon the bell- 

 margin. The 8 mouth-arms curve outwardly and upwardly in their lower halves. They are 

 a little longer than the bell-radius and each one is forked, each of the main forks being nearly 

 as long as the upper, undivided part of the arm. The forks give rise in turn to numerous 

 pinnate branchlets. There are numerous small, short appendages among the frilled mouths, 

 and those on the arm-disk at the ends of the perradial oral suture are longer, triangular in 

 cross-section, and prickly in appearance. The 4 subgenital ostia are circular and much 

 narrower than the spaces between them. The subgenital cavity is unitary and 4-lobed, as 

 in Cotxlovhiza. 



The central stomach gives rise to 8 large rhopalar and 24 inter-rhopalar radial-canals, 

 all of which extend straight outward to the bell-margin. All of the canals give offside branches 

 which form a wide, anastomosing network of vessels, the meshes of which are mainly polyg- 

 onal near the center, but rectangular near margin of disk. 8 canals arise from the stomach 

 at depressed areas near the sides of the perradial septa of the subgenital cavity. These canals 



