386 



MEDUSjE of the world. 



America. Probably the original specimens studied by Maas (1897) and those of VanhofFen 

 (1902) were not fully grown; those of the Siboga expedition described by Maas, 1905, being 

 considerably larger. Bigelow, 1909, finds that the manubrium varies greatly in length. 



Browne, 1906, records a small specimen from a depth of 250 fathoms to surface in the 

 Bay of Biscay. Bigelow, 1909, records it from the eastern tropical Pacific and states that 

 it belongs to the intermediate bathymetric fauna. 



Homoeonema platygonon Maas. 



Homaonema platygonon, Maas, 1893, Ergcb. der Plankton Exped., Bd. 2, K.c, p. 15, taf. 1, fig. 8.— Browne, 1903, Bergens 

 Museums Aarbog, No. 4, p. 21, plate 2, figs. 2, 3; 1906, Trans. Linnean Soc. London, Zool., ser. 2, vol. 10, p. 174- 



Bell somewhat higher than a hemisphere, with a low, small, dome-like apical projection 

 and thin walls. Bell 2 to 4 mm. wide and about 2 mm. high. There are 40 to 80 closely 

 crowded tentacles, all of similar appearance, but all were broken off short. There are 4 vesic- 



Fig. 232. — Homaonema platygonon, after Browne, in Bergens Museums Aarbog, 1903. 



Fig. 233. — Homaonema platygonon, after Browne, in Bergens Museums Aarbog. 



Fig. 234 — Homaonema platygonon, after Maas, in Ergeb. der Plankton Expedition. 



Fig. 235. — Homaonema militare, after Maas, in Ergeb. der Plankton Expedition. 



Fig. 236. — Homaonema amplum, after Vanhbffen, in deutsch. Tiefsee Expedition " Valdivia." 



ular lithocysts, near the interradial points of 4 alternate octants. Bell-margin studded with 

 nematocysts. Velum is about one-fourth as wide as bell-radius. There are 8 straight, fairly 

 wide radial-canals and a simple ring-canal. Stomach very short, being only about one-fourth 

 as long as depth of bell-cavity, and there are 4 short, simple lips. When fully expanded, 

 however, the mouth becomes a round opening according to Browne, 1906. 



The cavity at the base of the stomach extends up into the aboral dome-like apex of the 

 bell. The gonads form a broad band around the base of the stomach and extend outward on 

 both sides of each radial-canal for about one-third to one-half the length of the 8 canals. 



