144 THE MEDUSAE. 



variation which has led me to unite H. alba with H. conica, which differ in this 

 respect alone. In form they strongly resemble Maas's figure (: 06 b , pi. 1, figs. 3, 

 It) of H. racovitzae, being rounded and deep (not flat, as in the Geryonidae). 

 They are thus very different from the sexual organs of Halicreas. Van- 

 hbffen (: 02 b , taf. 9, fig. 5) figures them for the " Valdivia" specimen as 

 proximal, but lanceolate or oval, not circular ; he does not state whether 

 they were flat or globular. They are visible, though very small, even in 

 the smallest specimen, and in the large ones they are very prominent. 

 In the specimen represented in the photographs (PI. 3, figs. 1, 2) each 

 gonad contains many large eggs. 



Color. — The majority of the specimens were entirely colorless in life ; but 

 in one individual the entire entodermic system was of a very pale orange. 

 Vanhbffen states that the single " Valdivia" specimen was colorless. 



Homoeonema alba is undoubtedly an intermediate form. Vanhbffen has 

 recorded it from the southeastern Atlantic (42° 18' S. ; 14° 1' E.), while 

 the present collection shows that it is of wide distribution throughout 

 the Eastern Tropical Pacific. H. platygonon is so far known only from the 

 north Atlantic (Maas, between Iceland and Greenland; Browne, Norway and 

 Bay of Biscay), while H. racovitzae is recorded from the Antarctic (Maas, 

 : 06 b ). 



Homoeonema racovitzae Maas. 



Homoeonema racovitzae Maas, : 06 b , p. 10, pi. 1, figs. 3, 4 '> pi- 2, fig. IS. 



In addition to Homoeonema alba the collection contains two specimens 

 of a second species of the genus taken at Stations 4667, 300 fathoms to 

 surface, and 4676, 300 fathoms to surface. In most respects they closely 

 resemble the II. racovitzae of Maas ; but since they lack the characteristic 

 pigmentation of the latter, as well as on account of the widely separated 

 localities of capture, identification with that species is only provisional. 



They are much smaller than II. alba, the two specimens, both of which 

 have well-developed gonads, measuring respectively 7.5 and 10 mm. in 

 diameter. The most important difference from II. alba is in the very small 

 Dumber of tentacles per octant, neither specimen having more than six 

 in any octant. This is precisely the number recorded by Maas (: 06 b ) for 

 // racovitzae, and is a strong reason for believing that the present speci- 

 mens belong to that species. Specimens of H.alba of the same size already 

 have about twice as many tentacles (ten to twelve per octant). The struc- 





