350 



MEDUSAE OF THE WORLD. 



Gonionemu 

 P 



Gonionemus "hornelli " Browne=G. suvaensis. 



us hornelli, Browne, 1905, Report Pearl Oyster Fisheries, Gulf of Manaar, Suppl. Report No. 27, Roy. Soc. London, 

 149, plate 1, fig. 6; plate 2, fig. 4— Bigelow, H. B., 1909, Mem. Mus. Comp. Zool. at Harvard College, vol. 37, p. 106. 



Bigelow has decided that the apparent grouping of the tentacles in this medusa is due 

 solely to the 16 lithocysts which divide the tentacles into 16 linear groups, in no sense 

 comparable with the tentacle-clusters of Gossea. He concludes, therefore, that this medusa 

 is actually G. suvaensis. I present Browne's clear description herewith, for this was in 

 proof before the appearance of Bigelow's excellent paper upon the medusae ot the eastern 

 tropical Pacific, and it will serve as a means of reference to the medusa. 



Bell hemispherical, 6 mm. wide, with moderately thick walls. About 70 tentacles, all 

 with adhesive pads on their exumbrella sides near middle of lengths where the tentacles 

 are contracted. These tentacles are about equally spaced around the margin, but are arranged 

 in 16 groups in accordance with size. The 16 radial, adradial, and interradial tentacles are 

 long and the remainder are smaller, those nearer the long tentacles being longer than the 

 tentacles farther away. The radial and interradial groups contain each about 5 tentacles, 

 and the adradial clusters only about 4 tentacles. This tendency toward grouping exhibited by 

 108. '99- 



Fig. 198. — Gonionemus depressus, after Goto, in Mark Anniversary Volume. 

 Fig. 199. — Gonionemus suvaensis, after Bigelow, in Bull. Museum Comp. 



Zool. at Harvard College. 

 Fig. 200. — Bell-margin of Gonionemus suvaensis, after Bigelow, in Bull. 



Museum Comp. Zool. at Harvard College. 



the tentacles recalls the condition seen in Gossea, but is not so well marked. The tentacles all 

 project from the exumbrella sides of the margin, their entodermal cores piercing the gallert. 

 The tentacles are profusely ringed with nematocysts. There is a globular marginal bulb at 

 the base of each tentacle. There are 16 lithocysts on the subumbrella side of the margin, 

 between the 16 groups of tentacles, adjacent to the circular canal. Velum fairly broad. 4 

 broad radial-canals. Stomach cruciform, mounted upon a short, broad, conical peduncle. 

 4 short, simple lips. The gonads are developed upon the distal ends of the radial-canals very 

 near the circular canal. They are small, deeply folded and lobed, and extend laterally on both 

 sides of the canals, so that they are about twice as wide as they are long. The ova are large. 

 Pearl Banks, Gulf of Manaar. between Ceylon and India. A single specimen was studied by 

 Browne. 



Genus CUBAIA Mayer, 1894. 



Cubaia, Mayer, 1894, Bull. Museum Comp. Zool., vol. 25, p. 237; Ireniopsis, Ibid., p. 238; 1904, Mem. Nat. Sci. Brooklyn 



Inst. Museum, vol. I, No. I, p. 19.— Bigelow, H. B., 1909, Mem. Mus. Comp. Zool. at Harvard College, vol. 37, p. 102. 



Gonionemoides, Mayer, 1900, Ibid., vol. 37, p. 62.-Browne, 1904, Fauna and Geog. Maldive and Laccadive Archipelagoes, 



vol. 2, p. 738. 



The type species is Cubaia aphrodite, of Cuba, the Bahama and Florida reets. 



