8 Universily of (■alifornia Puhlications in Zoology [Vol. 13 



Euphausia gibba Sars 



PI. 1, fig. 2; pi. 2, figs. 26, 33, 36 

 ibuphausia gihba Sars. (] 885), p. 9], pi. 16, figs. 1-8. 



Hansen once stated (1905b, p. 17) that this form is identical with 

 E. pseudogilha Ortmann (Ortmann, 1893, p. 12, pi. 1. fig. 6), but 

 later restored pseudogihha to good standing (rian.sen, 1909, p. 97, pi. 

 14. figs. 4a-e). I am nnable to say whether the two species are truly 

 distinct, but our specimens closely resemble gihha. According to 

 Hansen (1905b, p. 17) Sars's figures are in part inaccurate, but .judg- 

 ing from them and from the notes given by Hansen concerning such 

 forms as liemigib'ba and paragihha (Hansen, 1909, p. 100) the only 

 difference that I can detect between the San Diego specimens and 

 those described as gihha lies in the little rounded extension of the 

 forward margin of the second joint of the antennule at the outer 

 angle (pi. 2, figs. 33, 36). So far as I know this is not mentioned 

 elsewhere, but it occurs constantly in our specimens. The leaflet 

 at the distal end and on the inner side of the first joint of the anten- 

 nule is shown in figure 26 (pi. 2). The extension of the third ab- 

 dominal segment is as shown by Sars (1885, pi. 16, fig. 1). There 

 would be no justification at present for making a new species to 

 receive the forms from this region, especially as we do not know the 

 structure of the copulatory organs of the males. 



The largest female is 23 mm. long, the smallest 10 mm. 



Genus Nyctiphanes Sars 



Nyctiphanes Sars (1885), p. 14 

 Nyctiphanes, Holt and Tattersall (1905), p. 103. 

 Nyctiphanes, Zimmer (1909), p. 9. 

 Nyctiphanes, Hansen (1911), p. 17. 



According to Sars the main characteristic of this genus is the ' ' re- 

 flexed leaflet" on the base of the peduncle of the antennules in front 

 of the eyes (pi. 1, see figs. 6 and 13). This affords a means of easy 

 recognition of the genus, at least among the Schizopoda of this region. 

 The outer ramus is lacking in the seventh and eighth pairs of feet in 

 the female (Zimmer, 1909. p. 9) and the endopodite of the seventh 

 pair consists of two long joints, while that of the last pair is very 

 rudimentary, not jointed and without setae. The females carry the 

 eggs in two sacs. The copulatory organs of the males are charac- 

 terized by the platelike or leaflike character of the inner lobe, in which 

 the outer margin is finely serrated, while the proximal and terminal 



