PELAGIC ANIMAL LIFE 



583 



represented by few specimens, though widely distributed. Hardly any 

 of the " Challenger " species described by G. O. Sars are found in the 

 Norwegian Sea. 



The Schizopoda play a great part in northern waters, where the 

 numerous species occur in enormous numbers, sometimes near the bottom 

 and sometimes near the surface ; the fishermen term them " Kril." They 



Fig. 420. 



Meganyctiphanes notvegica, M. Sars {\). This form has 

 highly phosphorescent organs on the under side of the 



are mostly colourless, transparent, with large red spots around the mouth, 

 and have generally the appearance of small prawns with black stalked 

 eyes. The most important species are Meganyctiphanes norvegica (Fig. 

 420) and Thysandessa longicaudata. The closing-net samples determined 



by Sars included some Schizopoda, 

 Amphipoda, and Isopoda (see list, pp. 

 654-655)- 



The great majority of the species of Amphipoda. 

 Amphipoda inhabit the warm oceans, 

 where they occur mostly in the upper 

 400 metres of water. Woltereck has 

 described some very remarkable deep- 

 water forms belonging to the genera 

 Lanceola and ScypJiolanceola (Fig. 421). 

 The members of the latter genus have 

 light-reflecting eyes, the retina of which is entirely transformed and 

 provided with peculiar cornet-shaped reflectors. They were previously 

 considered rare, but according to Woltereck, who is describing our 

 material, they were taken in great quantities during the cruise of the 

 " Michael Sars." Another deep-sea form is the large transparent 

 Cystosoma with splendid red eyes, which was taken in both our 

 southern and northern sections in depths exceeding 500 metres (Fig. 

 422). One of the most striking types is the genus PJironima, of the 

 family Hyperidae. Most of the Hyperidae make themselves a house of 

 the empty mantle of a Salpa or Doliohini, and lay their eggs in the 



Fig. 421. 



Scypholanceola agassizii, Woltereck. 

 (From Woltereck.) 



