tik! 
Gen. Nyctiphanes, Sars. 
1883. Nyctiphanes, Sars, Vid. Selsk. Forhandl. Christiania, 
Nos7icp: 23: 
1885. Nyctiphanes, Sars, Challenger Schizopoda, Reports, Vol. 
Petr. ps Leak 
1889. Nyctiphanes, Gerstaecker, in Bronn’s Thierreich, Vol. V., 
Pt 2) pe Gq: 
1893. Nyctiphanes, Stebbing, History of Crustacea, p. 263. 
Whereas in Euphausia both the fourth and fifth pairs of 
peraeopods are rudimentary, in Thysanopoda and Nycttphanes, 
it is only the fifth pair that is absolutely degraded, but while in 
Thysanopoda the fourth pair resembles those which precede it, 
in Nyctiphanes the terminal three joints are wanting. The 
flagella in both pairs of antennae are elongate, and in the first 
pair the first joint carries a peculiar “ leaflet ’’ or process reflexed 
over the eye. The female is characterized by the presence of a 
double ovisac. 
Nyctiphanes australis, Sars. 
1883. Nyctiphanes australis, Sars, Vid. Selsk. Forhandl. Chris- 
tiania, No. 7, p. 24. 
1885. Nyctiphanes australis, Sars, Challenger Schizopoda, Re- 
ports; Vol, XIDLY ppx1r57 50) Pl. 20, Ply 21, fies. 
i728. 
The rostrum is triangular, not elongate; the carapace is 
without lateral denticles, with the hind margin produced on 
either side beyond an emarginate central lobe. The eyes are 
large, pyriform. The outer margin of the first joint in the first 
antennae is produced into a sharp tooth, and the leaflet has its 
apex acute, upturned. The scale of the second antennae does 
not reach the end of the peduncle. The limbs are slender, the 
third and fourth peraeopods in the female being devoid of an 
exopod, which in the male they carry. The rudimentary fifth 
peraeopods consist of a broad basal joint surmounted by another 
that is slender, curved, obtuse-ended, and soft. The third joint 
in the appendages from the first maxillipeds to the fourth 
peraeopods is successively longer ; but in the third peraeopods 
the terminal three joints, which in the preceding appendages 
have a combined length greater or not less than that of 
the fourth joint, fall abruptly short of that length, pre- 
paratory as it were to disappearing altogether from the fourth 
