LISTS OF SPECIES BY STATIONS 



51 



Station 41 

 November 10, 1928; 1° 37' S, 86° 58' \V; bottom depth, 2568 m; 74 species 



Depth of tow, m 

 Temperature, °C 

 Salinity, 0/00 

 \'ohinie of tow, cm' 



Acarlia clanae 



Acrocalanus gibber 



gracilis 



longicornis 



Aegisthus spinulosus 



Calanus tonsus 



Calocalanus pavo 



styliremis 



Canthocalanus pauper. . . . 



Centropages furcatus 



Clausocalanus arcuicornis. 



furcatus 



Clytemnestra scutellata. . . 

 Corycaeus agilis 



crassiusculus 



pumilus 



speciosus 



typicus 



Eucalanus attenuatus 



crassus 



elongatus 



monachus 



mucronatus 



Euchaeta acuta 



marina 



Euterpina acutifrons 



Farranula carinata 



curta 



gibbula 



gracilis 



Gaidius tenuispinus 



Haloptilus longicornis 



ornatus 



Ik'terorhabdus papilliger. . 

 Labidocera acuta 



detruncata. juv 



I.ubbockia squillimana. . . . 



Lucicutia clausii 



flavicornis 



longicornis 



Microcalanus pusilius. . . 



pygmaeus 



Microsetella rosea 



Neocalanus gracilis 



tenuicornis 



Oithona attenuata 



plumifera 



similis 



spinirostris 



Oncaea conifera 



curta 



media 



minuta 



subtilis 



tenella 



venusta 



Paracalanus parvus 



Phaenna spinifera 



Pleuromamma gracilis. . 



Pontella danae 



Pontellina plumata 



Pseudocalanus minutus. 

 Rhincalanus cornutus. . . 



nasutus 



Sapphirina auronitens. . 



opalina 



Scolecithricella bradyi . . 



Scolecithrix danae 



.Spinocalanus abyssalis. . 

 Temora discaudata 



longicornis 



Undinula caroli 



darwinii 



\'ettoria granulosa 



29 

 f 



Id' 



r 

 1 



The temperature dropped 6° in the 100 meters, the salinity 

 rose 1 point, and the h\drogen-ion concentration diminished 

 a little. The volume of the surface tow was four times that 

 of the 50-meter tow and two and a half times that of the 100- 

 meter tow, although its length was only one-sixth greater. 

 Fort\-se\en species (63 per cent) were each confined to a 

 single depth and 12 were present at all three depths. Corycaeus, 

 Eucalanus. and Oncaea were each again represented by 5 to 7 

 species, but Candacia was entirely absent. The vertical dis- 

 tribution was 36 species at the surface, 34 in the SO-meter 

 tow, and 44 in the 100-meter tow. Both Rhincalanus species 

 were present at all three depths, instead of being confined to 

 the deeper tows as usual. Three of the Farranula species 

 appeared only in the surface tow, and 1 species was equally 

 di\ided between the surface and the 100-meter tow. Sim- 



ilarly, 2 of the Acrocalanus species were confined to the 

 surface tow and the third species was confined to the 100- 

 meter tow. Of the Corycaeus species, 1 appeared only in the 

 two deeper tows, 1 appeared at all three depths, 2 were con- 

 fined to the surface tow, and 1 to the 100-meter tow. Similar 

 differences can be found among the Oithona and Oncaea 

 species. 



A careful study of any of these station records where a 

 large number of species of the same genus are present sup- 

 ports the suggestion of Rose (see p. 13) that the adaptation of 

 copepods to light varies with each species. It will also go far 

 toward removing opposition to his further suggestion that 

 possibly such adaptation varies with each individual. The 

 inconsistencies which so frequently confront us can hardly be 

 explained on any other assumption. 



