COPEPODA III 



Variations etc. In a single young female of stage V the third seta of the left caudal rami 

 was dichotomous. 



Sac-shaped "parasits" like those described in G. tenuispinus were found in four adult females 

 and in a young male from St. 183. 



Occurrence. The Ingolf Exp. has not taken this species, the S/S Thor has gathered it at the fol- 

 lowing stations. 



19/6 1904 St. 152 65^00 L. N. 28°io L. W. I y? (V). 



"/y 1904 St. 183 6i°30 L. N. 17-^08 L. W. Yt. 1800 M. Wire 8 f?, 2 y? (V), 5 yc? (V). 



"/s 1904 St. 99 6i°i5 Iv. N. 9°36 L. W. if?. 



'5/6 1905 St. 82 5i°oo L. N. ii°43 L. W. Yt. 1200 M. Wire i y (III). 



8/6 1905 St. 72 57°52 Iv. N. 9°53 L. W. Yt. 1500 M. Wire i f?, SY? (V), \y S (V), i y? (IV), i y<? (IV). 



31/8 1905 St. 167 57=46 L. N. 9°55 L. W. Yt. 1500 M. Wire i yc? (V), i y? (IV). 



Distribution. The species has been taken at several stations by the Monaco Expedition, and 

 is fairly common on the west coast of Ireland "at depths of from 330 to 1150 fathoms". According to 

 Wolfenden it is "anschinen im Atlantischen Ocean sehr haufig, erscheint von dort auch in den 

 Fangen des "Gauss" und erstreckt sich nach Norden bis zur Westkiiste Gronlands". A single spec- 

 imen has by been collected the Siboga Exp. in the Malay Archipelago. 



Remarks. Between this species and Sars' description of G. lafifrons scarcely any difference 

 was found; in .spite of some small differences, enumerated above, it is certainly identical with Farran's 

 G. holti\ Wolfe n den's specimens were as a whole somewhat smaller, but in other respects scarcely 

 different. This species seems to differ from Scott's description by the shorter antennulae and the 

 different shape of the lamina of the maxilliped.s. 



30. Gaetanus ferox n. sj). 

 (Text-figs 28 a— b). 



Description, i^. Size: 3-4 mm., anterior division 2-6 mm.; urosome 078 mm. 



The shape of the body is most like that of Gaidius tenuispinus^ but the head dorsally terminates 

 in a proniinent, obtusely rounded keel (partly broken in the examined specimen). Below the frontal 

 spine the outline is almost straight, and is then convex towards the base of the clumsy rostrum, which 

 possesses two terminal points (text-fig. 28 a). The head and the first somite as well as the two last 

 thoracic ones are completely fused; the lateral corners are regularly rounded, but somewhat in front 

 of the margin are seen rather short slender spines, which probably only extend slightly beyond margin 

 (broken in examined specimen). The anterior division is 3-3 as long as the abdomen, which as usual 

 consists of 5 somites; the second somite is 1-5 as long as the third, which is a little longer than the first 

 and fourth; the fifth somite is just vi-sible from above. The genital pore is found on the left side. The 

 furcal rami are almost as long as wide; the St. 2 is somewhat longer than the abdomen (text-fig. 24 b). 



The antennulae extend distinctly beyond the end of the abdomen; the segments 20—21 are 

 completely fused, and the segment 22 has, at least on the left side, a characteristic structure, as it is 

 widened out from the narrower middle portion towards the base as well as towards the tip. 



