584 



DEPTHS OF THE OCEAN 



barrel-shaped abode (see Fig. 423). Phronima was taken in great 

 quantities in the surface waters during our southern and northern sections 

 across the Atlantic. 



In the Norwegian Sea two forms are very important : ParatJieviisto 

 oblivia (Fig. 424), which lives in the open sea, frequently even in very cold 

 water, and also in the Norwegian fjords ; and Euthemisto libellula, which 

 sometimes attains a length of 4^ cm., and lives in the icy waters of the 



Fig. 422. 

 Cystosoma neptuni, Gu^rin-M^n6ville. (After Wyville Thomson.) 



Polar Sea. Both these forms were taken also in the Atlantic, but only 

 in boreal areas (see list, pp. 654-655). A form which lives at great 

 depths in the Norwegian Sea is Cyclocaris giiilelmi, taken by the Prince 

 of Monaco off the Lofotens and described by Gran. 



While capturing turtles at Station 56 we observed a great number of 

 deep-blue Isopoda belonging to the species Idotea metallica. 



Decapoda. The Decapoda include nearly all the large types of crustaceans, like 

 prawns, lobsters, crayfish, crabs, etc. The first deep-sea expeditions 

 captured a considerable number of decapod crustaceans in the trawls at 



