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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. 9 — 15 (female). Plate X, figs. 1 — 9 (male}. 



Gaetanus kruppii Giesbrecht, 1903, p. 202, pis. 7 &. S. 



Gaetanus major Wolfenden, 1903 (a), p. 125. 



Gaetanus major Wolfenden, 1904, p. 114, pi. 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, pis. 9 & 14. 



Gaetanus brevicornis Esterly, 1906, p. 56, pis. 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 Gaetanus 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 



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