48 
Three specimens, all females, of this species were found. Length 2,3 mm. 
With the exception of the slightly longer antennules, I see no difference between the | 
‘Siboga’ specimens, and the figures given by Farran. 
Gaetanus minor has hitherto only been known from the North Atlantic Ocean. 
5. Gaetanus kruppii Giesbrecht. Plate IX, figs. g—15 (female). Plate X, figs. 1—g9 (male). 
Gaetanus kruppi Giesbrecht, 1903, p. 202, pls. 7 & 8. 
Gaetanus major Wolfenden, 1903(a), p. 125. 
Gaetanus major Wolfenden, 1904, p. 114, pl. IX, figs. 7 & 8. 
Gaetanus kruppi Sars, 1905 (a), p. 4. 
Gaetanus major Farran, 1905, p. 33. 
Gaetanus major Pearson, 1906, p. 14. 
Gaetanus clarus Esterly, 1906, p. 57, pls. 9 & 14. 
Gaetanus brevicornis Esterly, 1906, p. 56, pls. 9 & 12. 
Gaetanus major Farran, 1908, p. 36. 
Gaetanus major van Breemen, 1908, p. 40, fig. 45. 
Gaetanus kruppi van Breemen, 1908, p. 41, fig. 47. 
All the specimens obtained by the ‘Siboga’, were found in plankton collected with the 
HENSEN vertical net at the following stations. 
Stat. 118 (900 metres to surface). — Stat. 141 (1500 metres to surface). — Stat. 143 (1000 
metres to surface). — Stat. 243 (1000 metres to surface). — Stat. 276 (750 metres to surface). 
Female. This Gaefanus is not unlike a large example of Gaetanus armiger, but it can 
be distinguished from that species on careful examination. 
The antennules extend beyond the end of the furca, by the last two-joints. The cephalic 
spine is small, but quite visible when the copepod is seen from the dorsal aspect. The spines 
of the last thoracic segment are very small, and are only about one-third of the length of the 
genital segment. The combined length of the abdomen and furca, is distinctly less than one- 
third of the total length of the cephalothorax, from the apex of the frontal spine to the base 
of the genital segment. The genital.segment is considerably longer than the combined length 
of the next two segments. The furcal joints are about as long as broad, and are shorter than 
the anal segment. The rostrum is small and is distinctly bifid at the apex. The lamella on the 
ventral margin of the first joint of the second maxillipedes is distinctly pointed and deeply 
excavated. The exopodite of the first pair of feet is distinctly three-jointed. The first joint of 
the basiopodite of the fourth pair of feet is furnished with a number of fine bristles on its 
inner margin. Four specimens were found. Length 5,7 mm. 
Adult male. This resembles the female in general appearance, but the antennules are 
shorter, and the proportional lengths of the abdominal segments are different. 
The antennules extend slightly beyond the middle of the abdomen, and are furnished 
with a number of sensory organs placed along the dorsal margin of the first or basal half. The 
frontal spine is stronger than in the female, and the frontal margin of the head when viewed 
from the side is seen to have a distinct swelling. The spines of the last thoracic segment are 
short. The combined length of the abdomen and furca, is equal to about one-third of the total 
48 
