COPEPODA 71 



proper; laterally a series of short setae is observed (PI. I fig. zoa), and in front of these, partly on the 

 oral surface, a group of short spines or granules is observed. Orally we find on each side an inner and 

 an outer series of delicate bristles, arranged in a short posterior and a long anterior division. As far 

 as the structure of the labium etc. is concerned I refer to the fig. lob. 



f c?. Size of male 1-63 mm. 



The thoracic somite IV and V are as seen in the text-fig. 15 b well separated. The antennulae 

 have the articular-membranes between the segments 8^9 and 10, 10 and n, n and 12 rather in- 

 distinct; the antennulae become rather suddenly narrower beyond segment 14, which is wider than 

 15. The first to ninth segments possess two bristles in addition to one or two "Aesthetasken" ; in the 

 following segments, except in the I2th, no distinct proximal seta (Spr.) is observed, but small incisions, 

 corresponding to their insertions; "Aesthetasken" are observed in several of the segments. The oral 

 appendages are as shown and partly figured by Sars rather rudimentary. The maxillulae show the 

 following features. The Le possesses 7 short bristles; the Li I has only a few rudimentary setae, and 

 the rather prominent Li II III have 3 short delicate bristles each. The Basp. has 5 and the Ri I III 

 4-J-4 + 6 bristles, of which those of Ri III are fairly long and slender. The Re bears n partly power- 

 ful hairs. The mandibles are figured by Sars; the antennae, the maxillae and the maxillipeds are 

 less powerful, but in the main features alike those of the female. The labrum and labial appendages 

 show exteriorly a structure scarcely different from that of the female. 



The Se of Re I pes I is even less developed than in the female. The structure of the fifth 

 pair of legs (cf. text-fig. 15 c) is in some points different from Sars' description; between the Re I and 

 II on the right side an indistinct limitation is seen. 



Y (St. V). Size: 1-45 mm.; anterior division roo and the abdomen 0-45 mm. 



The shape of the body is scarcely different from that of the female; there is indication of 

 articulation between the head and first thoracic somite; the two last thoracic somites are, as seen in 

 text-fig. 15 d, well developed. The oral and natatory appendages are scarcely different from those of 

 the females. The structure of pes V is shown in text-fig. 14 e. 



Occurrence. The Ingolf Expedition has taken 2 mature females, a single mature male and 

 two young ones (St. V) 26 /e 1895 2 p. m. V 1 . 2000 fathoms St. 25 633o Lat, N. 5425 Long. W. 



Distribution. This species has been taken at 2 different stations in the polar seas in about the 

 8oth degree of latitude and the 1341!! degree of longitude east as well as at 8i32 L. N. by R0mer 

 and Schaudinn, on the coast of Norway (Osterfjord Norway in the depth from 400 600 metres), 

 and in moderate numbers on the west coast of Ireland "at all depths from 200 to 1000 fathoms". Ac- 

 cording to Giesbrecht it is found "99 132 W. 3 S. 14 N. In 10004000 Meter Tiefe". 



Remarks. The female described by Mrazek as Spinocalanus Schaudinni is certainly identical 

 with the mentioned Species. His male, however, seems in rather important features to differ; in his spec- 

 imen the segments VIII to XIV of the antennulae are completely fused (Taf. V fig. i), and the pes V 

 differs distinctly, especially by the Ri, the terminal seta of which just reaches beyond the end of Re I. 



