i88 



COPEPODS OF LAST CRUISE OF CARNEGIE 



Gaetanus minor Farran 



[Gaetantis minor Farran, Ann. Rept. Fisheries, Ireland, 1902- 

 03, pt. 2, app. 2, p. 34, pi. 5, figs, i-ii, 1905.] 



This species was taken in a nocturnal surface tow between 

 stations 35 and 36 and in the vertical tow from a depth of 

 1000 meters at station 64. The former proves that the species 

 migrates to the surface in the night; the latter suggests that 

 the regular tows were not deep enough for this species in the 

 daytime. In support of the latter suggestion, all the Siboga 

 specimens were taken in vertical hauls from considerable 

 depths. 



Genus GAIDIUS Giesbrecht, 1895 



Gaidius affinis G. O. Sars 



[Gaidius affinis G. O. Sars, Bull. Mus. oceanogr. Monaco, no. 

 26, p. 9, 1905.] 



One specimen of this species was found in the vertical tow 

 from 1000 meters at station 64 in the southeastern Pacific. 

 It is smaller than brevispinus but larger than tenuispinus. It 

 is probably more widely distributed than this single locality 

 would indicate, but stays below 100 meters in the daytime. 

 Sars (1905, p. 9; 1925, p. 47) reported this species from both 

 the Adantic and the Pacific oceans in vertical hauls from 

 depths of 1500 to 4800 meters. 



Gaidius brevispinus G. O. Sars 



[Gaidius brevispinus G. O. Sars, Norwegian North Polar 

 Exped., 1893-1896, Sci. res., vol. 5, Crustacea, p. 68, pi. 19, 

 1900.] 



A few specimens were found in the 100-meter tow at 

 station 8 in the Atlantic, and the species was found nowhere 

 else during the cruise. This is a boreal species, and has been 

 reported from the Arctic Ocean and the North Adantic. All 

 Sars' (1903, p. 162; 1925, p. 48) specimens were taken in 

 vertical hauls from depths of 1700 to 2000 meters. 



Gaidius tenuispinus (G. O. Sars) 



[Chiridius tenuispinus G. O. Sars, Norwegian North Polar 

 Exped., 1893-1896, Sci. res., vol. 5, Crustacea, p. 67, pi. 18, 

 1900.] 



This species was found in the southeastern and northern 

 parts of the Pacific. It was taken twice in the 50-meter tow, 

 5 times in the 100-meter tow, and once in the vertical tow 

 from 1000 meters at station 64. The records are all expressed 

 in numerals, indicating that the species is nowhere abun- 

 dant. Since it did not occur anywhere at the surface, it is 

 evidendy negative to light. It was reported by Sars (1903, 

 p. 162; 1925, p. 46) from several localities in the North 

 Adantic and even in the Arctic Ocean, and is a boreal form. 



Genus HALOPTILUS Giesbrecht, 1898 



This genus was well scattered over both oceans, but 

 showed several large gaps in distribution. No species was 

 found in the first thirteen stations of the Atlantic, or at 

 stations 58 to 68 in the Pacific (except at station 67 and in 

 the looo-meter haul at station 64), or at stations 82 to 93 and 



117 to 130. All the species, without exception, were confined 

 to the two deeper tows, especially the loo-meter tow. The 

 fact that no species of this genus appeared in any of the 

 nocturnal surface tows would suggest that the genus does 

 not take part very often in the vertical migrations. 



Chart 9. Daytime vertical distribution of species of Haloptilus: 

 (i) acutijrons, (2) angusticeps, (3) longicornis, (4) ornatus, 

 (5) oxycephahis, (6) phimosus, (7) spiniceps. One species was 

 confined to the 50-meter tow, two to the 100-meter tow, and the 

 other four appeared only in the two deeper tows, with the greater 

 abundance in the loo-meter tow. This is a more uniform vertical 

 distribution than that of some of the other genera, and all the 

 species react similarly to their environtnent. 



Haloptilus acutifrons (Giesbrecht) 



[Hcmicalanus acutifrons Giesbrecht, Fauna und Flora des 

 Golfes von Neapel, vol. 19, pp. 384, 398, pi. 3, fig. 11; pi. 27, 

 figs. 4, 12, 18, 26; pi. 42, figs. 12, 20, 1892.] 



This species was present in 3 5Q-meter tows and in 14 

 loo-meter tows, and in the vertical tow from 1000 meters at 

 station 64, all in the Pacific Ocean. With a single exception, 

 every one of the abundance records is a numeral, and twelve 

 of them were single specimens. In this connection it is 

 worthy of note that the species did not appear at all in the 

 Siboga plankton or in the Ingolf plankton. Its scarcity in the 

 Carnegie plankton, therefore, can hardly be due to the fact 

 that the tows (with one exception) did not descend below 

 100 meters. It has been recorded by Sars ( 1925, p. 250) and 

 Farran (1929, p. 267) from the North Atlantic and the 

 Arctic Ocean. 



Haloptilus angusticeps G. O. Sars 



[Haloptilus angusticeps G. O. Sars, Bull. Inst, oceanogr. 

 Monaco, no. loi, p. 20, 1907.] 



A single female was taken in the 50-iTieter tow at station 

 116 in the western Pacific off the coast of Japan, and this was 

 the only record for the cruise. Like the preceding species, 

 this one did not appear in the lists of any of the plankton 

 expeditions, but has been reported by Sars ( 1925, p. 246) 

 from the North Atlantic and the Mediterranean. The species 

 is thus very rare, and this Carnegie record is the first one 

 from the Pacific Ocean. 



Haloptilus longicornis (Claus) 



\Hcmicalanus longicornis Claus, Die freilebenden Copepoden, 

 p. 179, pi. 29, 1863.1 



This is the most numerous and widely distributed species 

 of the genus, and was found everywhere in the teinperate 

 and tropical regions of both oceans. It was present in 23 50- 



