HYDROMEDUSAE, SIPHONOPHORES, AND CTENOPHORES. 



339* 



The general structure of the superior nectophore of D. contorta 

 has been described in detail by its discoverers; the present series 

 agrees very well with their account except for one point already 

 noted in my discussion of the eastern Pacific collection (1911ft). 

 Instead of there being five ridges at the apex, as Lens and Van 

 Riemsdijk state, there are only four, for the right ventral invariably 

 arises a short distance below the apex. I have seen no variation from 

 this in either Pacific or Philippine specimens. 



The series is especially interesting because three specimens have 

 buds for inferior nectophores so far developed that there is no doubt 

 of their future fate. This discovery shows that contorta is unques- 

 tionably a diphyid, not a monophyid: the absence of special necto- 

 phores in the groups of appendages (Lens and Van Riemsdijk, 1908) 

 places it in Diphyes rather than in Diphyopsis. 



The peculiar asymetry of contorta and the form of the somato?- 

 cyst are so characteristic that it is not likely to be confused with any 

 other species. The species is so far known from the Malay Archi- 

 pelago, the eastern tropical Pacific, Japan (Bigelow, 1913), the Phil- 

 ippines, the Seychelles (Moser, 1913), and has recently been recorded 

 by Moser (1913) from the Atlantic. 



Genus DIPHYOPSIS Haeckel. 



DIPHYOPSIS BOJANI (Eschscholtz) Bigelow. 



Eucloxia bojani Eschscholtz, 1825, p. 743, pi. 5, fig. 15. 



Diphyes bojani Bigelow, 1911&, p. 251, pi. 7, fig. 2, 3: pi. 8, fig. 6; pi. 9, 



figs. 1, 2 ; pi. 10, figs. 2, 3 ; pi. 11, fig. 5 ; pi. 12, fig. 1, 1918, p. 424, [full 



synonym j']. 



Diphyopsis bojani — material examined. 



According to Moser (1911, 1913) Ersaea bojani Eschscholtz, which 

 I was unable (1911&) to connect definitely with any Diphyid, be- 

 longs to this species; and she also unites D. bojani with the Atlantic 

 D. steenstrupi Gegenbaur. This I can myself confirm (1918) from 

 Atlantic specimens recently studied. D. serrata Chun probably be- 

 longs here also. 



These few examples add little to the account of the eastern Pacific 

 and "Bache" series (1911&, 1918). 



74S41— 19— Bull. 100, pt. 5 5 



