226 THE SCHIZOPODA. 



NYCTIPHANES G. O. Sabs (1883). 



As the endopod of the penultimate pair of thoracic legs is long, but only 

 two-jointed, this genus ought to find its place between Thysanopoda and Eu- 

 phausia, as already stated by Ortmann in 1894. G. 0. Sars established the 

 genus on a species. A'', australis G. O. S., from the Southeastern and Eastern coasts 

 of Australia, and referred Thysanopoda norvegica M. Sars to the same genus, 

 believing that T. couchi Bell possibly might be identical with the latter form. 

 In 1905 Holt and Tattersall established the genus Meganyctiphanes on T. 

 norvegica, pointing out that it differed from Nyctiphanes G. O. S., comprising 

 N. couchi Bell and A^ austraUa G. 0. S., in the following particulars: — fifth and 

 sixth pairs of thoracic legs witli an endopod in both sexes, while an endopod 

 on these legs is present in the male and wanting in the female; furthermore, in 

 Nyctiphanes the antennular peduncle is " considerably stouter in the adult male 

 than in the female", but in Meganyctiphanes the same peduncle is "scarcely, 

 if at all" stouter in the male than in the other sex; finally, the females of Nycti- 

 phanes carry their eggs "in paired pyriform masses," but on Meganyctiphanes 

 ovisacs have never been found. I may add that the male copulatory organs 

 on the first pleopods afford excellent generic characters; in Meganyctiphanes 

 the organs are nearly as in Thysanopoda and the inner lobe short with its three 

 processes well developed as in that genus; in Nyctiphanes (Plate 6, fig. 2h and 

 fig. 3e) the inner lobe is quite peculiar, being extremely produced as an oblong, 

 more or less triangular plate with the outer margin sinuate and partly serrate, 

 and this lobe has the spine-shaped process well developed as in Meganyctiphanes, 

 while the terminal and the proximal processes are quite wanting. 



The genus Nyctiphanes comprises four species. Two species, A'', australis 

 G. O. S. and N. couchi Bell, were established in the earlier literature; in 1911 

 I i)ul)lishcd preliminary descriptions of the two additional species, N. simplex 

 H. J. H. and N. capcnsis H. J. H. and besides I pointed out that A', latifrons 

 lUig (1908) taken West of Northern Africa was established on very young speci- 

 mens of A^. couchii Bell. 



The Agassiz collection contains specimens of A^ simplex H. J. H., but for 

 various reasons, and especially as Ortmann has referred specimens taken by 

 Agassiz in the Pacific to N. australis, I redescribe also this species for com- 

 parison with A^ simplex. 



