. The Danish Ingolf-Expedition. Scientific expeditions; Arctic Ocean. 86 COPEPODA. The shape of the body is like Farran's description; the anterior division is 2-9 as long as the abdomen; the furcal rami are 1-4 as long as wide (text-figs 21 a—b). The mitcnnulac differ from those of Ch. obhisifrois by the 20 segment, which is a little longer than the second, which is again longer than segments 8 c\j 9. The Si I of the third basipodite of the mandibulae is longer and thicker than that of CIi. obtusifrons, bnt shorter than that of Ch. Poppei. In the other mouth appendages scarcely any difference
. The Danish Ingolf-Expedition. Scientific expeditions; Arctic Ocean. 86 COPEPODA. The shape of the body is like Farran's description; the anterior division is 2-9 as long as the abdomen; the furcal rami are 1-4 as long as wide (text-figs 21 a—b). The mitcnnulac differ from those of Ch. obhisifrois by the 20 segment, which is a little longer than the second, which is again longer than segments 8 c\j 9. The Si I of the third basipodite of the mandibulae is longer and thicker than that of CIi. obtusifrons, bnt shorter than that of Ch. Poppei. In the other mouth appendages scarcely any difference was ob- served. In the first pair of legs the Se Re I does not extend to the end of the segment. The segmentation of the legs is better developed than in CJi. obtusifrons^ as shown by Farran (text-figs 21 c—d). Occurrence. Though the Thor has only taken 3 f^ (of which one with spermatophor) ^/o 1905 St 72 57°57 L. N. 9°53 L. W. Yt 1500 M. Wire, I think that this species belongs to the fauna of the region explored by the Ingolf Expedition. Remarks. This species is according to Farran fairly common on the west coast of Ireland; its range was from 280 to 1000 fathoms. I think it is extremely doubtful whether the species which A. Scott refers to this species, from the Malayan Sea, really is identical with the Irish species. I think that Farran is right in regarding it as a species which forms a con- necting link between the much smaller Ch. Poppei and the much bigger Ch. obtusifrons^ of which the former is a distinct Arctic and tlie latter a Mediterranean form. As the females belonging to the Chiridius, as Giesbrecht defined it are very much alike, a thorough investigation of the differences between the existing species viz. those from the Siboga expedition, the thiee mentioned above and Wolf. (p. 212), which is very nearly related to if not identical with Ch. gracilis, is needed. Text-fig. 21. Chiridius gracilis Farrau. a. Genital somite in dorsal view X 60. b. F
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectscienti, bookyear1915
