72 



COPEPODS OF LAST CRUISE OF CARNEGIE 



Station 58 

 December 22, 1928; 36° 51' S, 104° 05' W; bottom depth, 3810 m; 36 species 



Depth of tow, m 

 Temperature, °C 

 Salinity, o 'oo 

 X'olume of tow, cm' 



Acrocalanus gibber 



gracilis 



Canthocalanus pauper. . , . 

 Clausocalanus arcuicornis. 



furcatus 



Corycaeus crassiusculus. . . 



pumilus 



typicus 



Eucalanus elongatus 



Euchaeta acuta 



Euchirella rostrata 



Farranula curta 



rostrata 



Lucicutia clausii 



Mecynocera clausi 



Megacalanus longicornis. . 

 Microcalanus pusillus 



pygmaeus 



Neocalanus gracilis 



robustior 



tenuicornis 



Oithona brevicornis. . . . 



similis 



spinirostris 



Oithonina nana 



Oncaea conifera 



media 



minuta 



similis 



venusta 



Paracalanus parvus 



Pleuromamma gracilis. . 

 Pseudocalanus minutus. 



Sapphirina angusta 



Scolecithrix danae 



Undinula darwinii 



From a low surface temperature there was a drop of 4?5 in 

 the upper 100 meters, and the salinity and hydrogen-ion 

 concentration remained moderately high and constant. Only 

 4 species appeared at the surface, 24 in the 50-meter tow, 

 and 25 in the 100-meter tow. Twenty-one species (60 per 

 cent) were each confined to a single tow and only 2 were found 

 in all three tows. This station is notable for the small number 



of species found at the surface. This may be due to the 

 fact that the great bulk of this tow was made up of cteno- 

 phores. These feed on copepods, among other creatures, and 

 when they swarm in large numbers, as they were doing here, 

 they would naturally reduce the number of the copepods. 

 This would also help explain the great drop in number of 

 species from 108 at station 56 and 80 at station 57 to 36 here. 



Station 59 

 December 24, 1928; 39° 51' S, 101° 04' \V; bottom depth, 4116 m; 24 species 



Depth of tow, m 

 Temperature, °C 

 Salinity, o/oo 

 X'olume of tow, cm' 



Acrocalanus gracilis 



Clausocalanus arcuicornis . 



furcatus 



Corycaeus flaccus 



Eucalanus elongatus 



mucronatus 



Euchaeta acuta 



Euchirella rostrata 



Farranula curta 



Macrosetella gracilis 



Mecynocera clausi 



Neocalanus gracilis 



Oithona attenuata 



brevicornis 



similis 



spinirostris 



Oncaea mediterranea . . . 



similis 



Paracalanus parvus 



Pleuromamma gracilis . . 

 Pseudocalanus minutus. 



Sapphirina angusta 



Scolocithri.x danae 



Undinula darwinii 



This station was next to the farthest south in the Pacific 

 and hence showed a low surface temperature, with a fall of 

 5° in 100 meters. The salinits' and hydrogen-ion concentration 

 were moderate and changed very little. Five species were 

 found at the surface, 15 in the 50-meter tow, and 21 in the 

 100-meter tow. Eleven species (46 per cent) were each con- 

 fined to a single tow and 4 were found at all three depths. 



Although the surface tow was shorter than the other two, its 

 volume was three or four times as great. Again this was due 

 to the large number of ctenophores it contained, which helps 

 to ex[ilain the small number of surface copepods and the still 

 further drop in the total number of copepod species. Scoleci- 

 thrix and the 2 species of Clausocalanus composed a very large 

 percentage of the SO-meter tow. 



