310 



MEDUSAE OF THE WORLD. 



canals; 12 others are of medium size, 3 of these being found in each quadrant. There are 

 also about 40 very small rudimentary tentacle-bulbs upon the bell-margin. There are neither 

 lateral nor marginal cirri. About 56 lithocysts alternate in position with the tentacle-bulbs, 

 each containing 2 or 3 spherical concretions. Velum well developed. There are 4 simple, 



171. 171a. 



Fig. 170. — Phonis elliceana, after Agassiz and Mayer, in Mem. Museum Comp. Zool. at Harvard College. 



Fig. 171.— Irenopsis hexanemalis, after Maas, in Craspedoten Medusen Siboga Exped. Aboral view of medusa. 



Fig. 171a. — Part of bell-margin of /. hexanemalis. 



narrow radial-canals and a slender circular vessel. The peduncle is about as long as bell- 

 diameter and projects considerably beyond bell-opening. Basal part of peduncle has the 

 shape of a 4-sided, truncated pyramid, while the distal part is long and tapers gradually 

 toward the stomach. The 4 radial-canals extend down the angles of the peduncle to the stom- 

 ach. Stomach is short and flaring; 4 well-developed, recurved, folded lips. The 4 gonads 

 are linear and developed upon the subumbrella region of the 4 radial-canals. 



The entoderm of tentacle-bulbs and gonads pink, stomach rosin-yellow. 



A single specimen of this medusa was found in an open net which was towed from a 

 depth of 150 fathoms to the surface ofF Funafuti Atoll in the Ellice Islands, tropical Pacific, 

 in December, 1899. 



Genus IRENOPSIS Goette, 1886. 



Irenopsis, Goette, 1886, Sitzungsber. Akad.Wissen. Berlin, Jahrg. 1886, p. 832.— Chun, 1896, Mitth.Naturhistorischen Museum 



Hamburg, Bd. 13, p. 5. 

 Non Irertiopsis, Mayer, 1894, Bull. Mus. Comp. Zool. at Harvard College, vol. 25, p. 238. 



Irenopsis, Browne, 1905, Report on Pearl Oyster Fisheries of Gulf of Manaar, Roy. Soc. London, Suppl. Report 27, p. 142. 

 Irenopsis, Maas, 1905, Craspedoten Medusen der Siboga Expedition, Monog. 10, p. 36. 



The type species is Irenopsis hexanemalis Goette of the coast of Zanzibar, Indian Ocean, 

 and Malay Archipelago. It is abundant in these regions. 



GENERIC CHARACTERS. 



Eucopidaewith6 radial-canals, 6gonads, 6 lips. No cirri. Numerous lithocysts. Stomach 

 mounted upon a peduncle. Hydroid unknown. 



Irenopsis hexanemalis Goette. 



Irenopsis hexanemalis, Goette, 1886, Sitzungsber. Akad. Wissen. Berlin, Jahrg. 1886, p. 832.— Chun, 1896, Mittheil. Natur- 



hihtur . Mus. Hamburg, Bd. 13, p. 5. 

 PhilaUdium tenue (abnormal specimen), Browne, 1904, Fauna and Geog. Maldive and Laccadive Archipelagoes, vol. 2, part 3, 



p. 730, plate 54, fig. 4; plate 57, fig. 16. 

 Irenopsis hexanemalis, Browne, 1905, Report on Pearl Oyster Fisheries, Gulf of Manaar, Roy. Soc. London, Supplementary 



Report 27, p. 142, plate I, fig. 4; plate 3, figs. 5-8.— Maas, 190$, Craspedoten Medusen der Siboga Expedition, Monog. 



10, p. 37, taf. 6, fign. 38-40. 



Bell flatter than a hemisphere, 12 to 18 mm. wide (see fig. 171). There are 30 to 50 

 short, slender, tapering tentacles with large, swollen, basal bulbs. These tentacles are less than 

 half as long as bell-radius, their outer ends usually helically coiled. There are 3 or more 



