INVERTEBRATE BOTTOM FAUNA 521 



most characteristic of the amphipods is Amathillopsis spinigera 

 (see Fig. 366), which has an extremely spinose body.^ The 

 cold area, moreover, like the plateaus and coasts, has its caprel- 

 lids climbing about among the sponges and hydroids, the most 

 numerous and common being Caprella spinosissima, whose body 

 is covered with dense strong spines. Among isopods we get 

 the remarkable Etcrycope gigantea belonging to a group with 

 very long legs that easily drop off; it has a relation not nearly 



Fig. 364. 

 Nymphon robusfum. Bell. (After Wyville'Thomson. ) 



SO big [Mti7inopsis typica) in the greater depths of the boreal 

 region and widely distributed throughout the arctic seas. 

 The isopod fauna is further represented, often in consider- 

 able quantities, by the genera Arcturus (A. baffini, see Fig. 

 367) and Astacilla (A. granulata). 



A sea- anemone, Allantadis parasitica, is another of the 

 most characteristic forms, attaching itself to the shells of snails 

 belonging to the species of Sipho and Neptunea. 



1 Other amphipods conspicuous owing to their size are Stegocephalus inflalus, the extremely 

 thick forepart of whose body makes it easily recognisable, Cleippides quadricuspis, with long 

 spines along the dorsal portion of its posterior segments, Anonyx sp. , etc. 



