Panama but, as the same species occurs in both localities, 

 it undoubtedly also occurs at intermediate points. There is 

 a broad gap between Attu Island (at the extreme western end 

 of the Aleutian chain) and Yezo Strait, on the two sides of 

 which different species occur. None of the dredge hauls along 

 the coast of Kamchatka and the Kurile Islands have ever 

 yielded any specimens. 



The bathymétrie ranges of the species of this genus in all 

 the localities where they occur have been given above ; it is, 

 however, instructive to consider them in a somewhat different 

 light. 



The range (in fathoms) over which the species extend in 

 each locality is as follows : 



Average 

 . ... 388 



Magellanic region 164 



Bay of Panama 496 



Mexico and Lower California... 5o5 



Off Southern California 1014 1014 



Off Northern California 200 



Off Oregon 286 



Off Washington 645 J 409 



Gulf of Alaska 619 



Bering Sea 297 



East coast of Japan 426 ) 



South coast of Japan 517 ) 



471 



The thermal ranges of the species of this genus in all the 

 localities where they occur have been given ; but it is instruc- 

 tive to consider them as the bathymétrie ranges have just been 

 considered. 



The thermal range (in degrees Fahrenheit) over which the 

 species extend in each locality is as fellows : 



Average 



Strait of Magellan 3°.i \ 



Bay of Panama 6°. 4 / q 0 35 



Mexico and Lower California. . . 6°. 3 i 



Off Southern California 110.6 



Off Northern California 70.2 



Off Oregon 40.8 J 80.4 



Off Washington 90. g ] 



Gulf of Alaska tio.6 



Bering Sea o°4 



East coast of Japan 14°. 7 (' 



South coast of Japan i5°4 } 



io°. 5 



(285) 



