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EIGHTH PACIFIC SCIENCE CONGRESS 



4000-6000 meters (example in Fig. 1), 3. Depth range 6000-10000 me- 

 ters, the trench-faunas. It remains to be seen how such a division will 

 work in detail; especially in the case of the trench faunas a certain 

 endemism may be expected. If animals really are adapted to live at 

 a pressure of e.g. 800-1000 atmospheres in the Philippine Trench, such 

 species will not be able to sjDread to other trenches. The extent of 

 endemism of the single trench fauna may also reflect to a certain degree 

 the relative age of the trench. 



In this connection it may be of interest to give a preliminary list 

 of the deepest records of a number of animal groups, as found by the 

 Galathea Expedition. 



TABj:.E I 



Deepest Records of a Number of Animal Groups. 

 Results from the Galathea Expedition. 



Group 



Depth, M. 



NUMTfER 



OF Species 



Trench 



Actlnaria . . . . 

 Echiuroidea . . 

 Holothurioidea 



Bivalva 



Polychaeta . . . 

 Amphipoda . . 



Isopoda 



Tanaidacea . . 

 Sipunculoidea 

 Crinoidea . . . . 

 Gastropoda . . 

 Hydrozoa . . . . 

 Asteroidea . . . 

 Echinoidea . . . 



Cumacea 



Neopterygii . . 



Porifera 



Cirripedia . . . 

 Brachyura . . . 

 Anthipatharia 

 Scaphopoda . . 

 Ophiuroidea . . 



Ascidia 



Scyphozoa . . . 

 Nematoda 

 Pycnogonida . 

 Alcyonaria . . . 

 Zoantharia . . . 

 Ostracoda . . . . 

 Bryozoa 



