TRACHYMEDUS.E — HOMCEONEMA. 



387 



The gonads, stomach, and radial-canals are yellowish-white in preserved specimens, all other 

 parts being colorless. 



Browne describes this species from the coast of Norway, Skjerstadfjord and Byfjord. 

 The Plankton expedition of 1889 found it somewhere in the Atlantic, according to Browne, 

 between Iceland and Greenland, in lat. 6o° N. According to Maas, 1906, this medusa is 

 found in deep water in the subtropical Atlantic. Maas states that the Arctic H. platygonon 

 is closely related to the Antarctic medusa called Haliscera alba by VanhSffen. This conclusion 

 he bases upon a recent study of Vanhoffen's own specimens. However, Vanhoffen states that 

 his Haliscera alba has a bell 35 mm. wide, whereas H. platygonon is apparently only about 

 4 mm. wide, so that the two species are apparently distinct. 



Homoeonema militare Maas. 



Homoeonema militare, Maas, 1893, Ergeb. der Plankton Exped., Bd. 2, K.c, p. 16, taf. I, fig. 1; Ibid., Craspcdoten Medusen 

 dcr Siboga Expedition, Monog. 10, p. 54. 



Bell miter-shaped with a well-developed apical projection and bulging (contracted ?) 

 sides. 7 to 10 mm. wide, 6 mm. high. Velum over 2 mm. wide. A large number (about 50) 

 of about equally developed tentacles. About 4 large, spherical lithocyst-clubs, each mounted 

 upon a short, thin stalk. 8 wide radial-canals with 8 wide, lancet-shaped gonads upon their 



237- 



Fig. 237. — "Isonema" amplum, after Maas, in Voyage Belgica. 



Side view above. Oral view below. 

 Fig. 238. — Homa-onema rnacrogaster, after Vanhoffen, in Val- 



divia Tiefsee Expedition. 



distal halves, above the ring-canal. Stomach large, 8-sided above, 4-sided below the middle. 



With 4 lips. When contracted the stomach is one-third to one-half as long as the depth of the 



bell-cavity. A single specimen found by Plankton Expedition north of the Bermudas in about 



N. lat. 38 from a depth of 400 fathoms. Later it was found in the Mediterranean by Lobianco. 



(See text-figure 235.) 



Homoeonema amplum Vanhoffen. 



Homxonema amplum, Vanhoffen, 1902, Wissen. Ergeb. deutsch. Tiefsee Expedition, Dampfer Valdivia, Bd. 3, Lfg. I, p. 65, 



taf. 10, fig. 21; taf. 11, fign. 24, 26, 27. 

 Isonema amplum, Maas, 1906, Expedition Antarctique, S. Y. Belgica, Medusen, p. 5, taf. I, fign. I, 2, 7; taf. 2, fign. 8, 12; taf. 

 3, fign. 14, 20. 



Bell 15 mm. wide, somewhat flatter than a hemisphere. Gelatinous substance quite thin, 

 thicker at apex. About ioo or more tentacles, all similar each to each. 4 to 8 marginal 

 lithocyst-clubs. 8 radial-canals. 8 spherical gonads upon the radial-canals adjacent to stomach; 

 these sometimes differ in size, 4 being large. The stomach is very small, urn-shaped with 



