82 



COPEPODS OF LAST CRUISE OF CARNEGIE 



Station 64 (b) 

 January ,S, 1929; 31° 54' S, 88° 17' W; bottom depth, 3879 m; 74 species 



Acartia danae f 



negligens r 



Acrocalanus gracilis c 



Amallophora typica 2 9 



Amallothrix valida 2 



Centropages calaninus 1 



rhiridiella sp., immature 3 



Chiridius poppei 19 



Clausocalanus arcuicornis c 



Corycaeus flaccus 2 



lautus 1 



longistylis 3 



Euralanus crassus 1 



elongatus 3 



mucronatus 2 



Euchaeta acuta 2 



spinosa f 



Euchirella intermedia 3 



messinensis 1 



rostrata I cT 



Gaetanus armiger 4 



kruppii, immature 1 cf 



miles 1 



minor 3 



Gaidius affinis 1 



Gaidius tenuispinus 3 



Haloptilus acutifrons 1 



longicornis 1 



plumosus 1 



Heterorhabdus abyssalis 3 



compactus 19 



papilliger 1 



Heterostylites longicornis 1 c? 



Lophothrix frontalis 1 



humilifrons 1 



Lucicutia clausii 3 



flavicornis 1 



longicornis 4 



Mecynocera clausi c 



Megacalanus longicornis 1 



princeps 2 



Metridia longa 4 



lucens 2 



princeps 3 9 



Neocalanus gracilis 2 



robustior 1 



Oithona similis r 



spinirostris 2 



Oncaea conifera c 



curta f 



Oncaea media 1 



niediterranea r 



notopa r 



similis f 



tenella 3 



venusta c 



Onchocalanus cristatus 19 



trigoniceps 19 



Pareuchaeta incisa 4 9 



Phaenna spinifera 1 



Phyllopus helgae 3 9 



PleuromaFiima abdominalis 2 



gracilis a 



robusta 3 



xiphias 5 



Pseudochirella divaricata 19 



Scaphocalanus magnus 19 



Scolecithricella auropecten 5 



bradyi 2 



Scolecithrix danae 2 



Undeuchaeta major 3 



plumosa 3 



Undinula darwinii f 



X'aldiviella minor 1 



This is the only instance during the entire cruise when a 

 towing was made below 100 meters. Here the net was lowered 

 to 1000 meters, drawn horizontally for 160 meters, and then 

 raised to the surface. The temperature was 3?8 C; the salinit\', 

 34.3 o/oo; the densit)', 32.0; the hydrogen-ion concentration, 

 7.76; volume of tow, 64 cm^; length of tow, 0.1 mile. Since 

 the net emplo\ed could not be closed, we have a combination 

 of a horizontal tow at a depth of 1000 meters and a \ertical 

 tow from 1000 meters to the surface. .As would be expected. 

 we find here man\- species (16) which were not obtained in 

 any other tow, and 4 others 1 of which was found elsewhere 

 in a 100-meter tow and 3 in a surface tow. Another noteworthy 

 fact is that 59 of the 74 species (80 per cent) were represented 

 by 5 individuals or less, 27 of them b>- solitary specimens. 

 Hence, although this deep tow added materially to the num- 



ber of species obtained, it was very meager in individual 

 specimens. Pleitromamma gracilis is recorded as abundant and 

 5 species are recorded as common; these are all, except Oncaea 

 conifera, abundant in the upper 100 meters, and of course 

 may ha\e been obtained there as the net was drawn to the 

 surface. Since the net was drawn horizontally at a depth of 

 1000 meters for a reasonable distance, the paucity of speci- 

 mens in the case of the 9 species mentioned above would seem 

 to suggest that none of them congregates at a depth of 1000 

 meters. On the contrary, their downward migration during 

 the daytime probably stops at a level between 100 and 1000 

 meters. That would explain why they were not taken in the 

 regular 100-meter tow, and wh>- so few of them were captured 

 as the net passed \erticalK' ii|)ward through tlie le\el where 

 they had stopped. 



