EEVISION OF THE FISH FAMILY LIPARIDAE 55 



callyodon — Washington to Bering Island. 



curilensis — Simushir Island, Kurile Group. 



mucosus — Pacific Grove to Kodiak Island. 



micraspidophorus — Agattu and Bering Island. 



greeni — Washington to Bering Island. Not in tide pools. 



beringianus — Washington to Bering Island. Tide pools. 



simushirae — Simushir Island. Tide pools. 



dennyi — Washington to Gulf of Alaska. 



gihha — Bering Sea. 



cyclostigma — Bering Sea. 



ochotensis — Okhotsk Sea. 



rhodosoma — Okhotsk Sea. 



ingens — Japan Sea. 



brisiolense — Bristol Bay. 



cephalus — Bristol Bay. 



tunicatus — Labrador to Greenland. 



herschelinus — Arctic coast of Alaska. 



agassizii — northern Japan. 



Certain of these species may be combined or divided when better 

 known. The distribution of some will be extended and of others 

 restricted. When this is done it will doubtless be seen that the 

 prmciple stated by Jordan applies to the distribution of the species of 

 Lijparis. 



Bathymetrical distribution. — The species of Liparis, as has been said, 

 are most common in the tide pools and do not descend below 250 

 fathoms. The greatest vertical distribution for any one species is 

 175 or possibly 212 fathoms for Liparis fucensis. Liparis dennyi 

 is known to range through about 100 fathoms. The majority of the 

 species range through less than 50 fathoms. It may be found that, 

 on account of the greater difference in temperature betw^een the 

 surface and bottom waters on the Japan coast, the species do not 

 have as great vertical distribution as on the American coast. 



Center of dispersal. — When we attempt to apply the criteria used 

 by Adams (1902) and Ruthven (1908) in finding the center of dis- 

 tribution of a group we find that, of those applicable, certain ones 

 point to northern Japan and the remainder to Bering Sea. At 

 present we shall not attempt to distinguish between these two regions 

 but shall designate Bering Sea as the center of dispersal for the genus. 



At the time when there was a land connection between Asia and 

 America (see J. P. Smith 1907) and the Arctic Current was prevented 

 from entering Bering Sea the waters of the North Pacific were tem- 

 pered by the warm Japan Current more than at present. The 

 species of this genus must have retreated to Bering Sea and may have 

 been exterminated there. When the land bridge subsided and the 

 cold Arctic Current again chilled the North Pacific the species of 

 Liparis remaining in Bering Sea or others from the Arctic Ocean 

 migrated southward along the Asiatic and American shore lines. The 

 subsidence of the land bridge across Bering Strait was at a sufficiently 



