REVISION OF THE FISH FAMILY LIPARIDAE 53 



find a very favorable environment. In fact a temperature of 40° F. is 

 favorable to most of the species. 



The favorable environment offered by the cold waters of this region 

 may account for the gigantic size attained by some of the species. The 

 four largest species of the genus, ranging in length from 430 to 485 mm. 

 are found in Japanese waters. One of these comes from a temperature 

 of 32.7° F., another from 33.9° F. The other two specimens lack 

 records. The largest species from the American coast is L. greeni and 

 reaches a length of 244 mm. 



The tide-pool species of the Atlantic coast of America extend as far 

 south as the coast of Massachusetts or possibly of Connecticut. This 

 is about the same latitude as the north of Hokkaido, their southern- 

 most distribution on the Asiatic coast. In both regions a northward- 

 moving warm current raises the temperature of the surface waters and 

 produces an unfavorable environment for these Arctic fishes. The 

 Gulf Stream is deflected to the northeast off Nova Scotia and warms 

 the shores of Europe to such an extent that these fishes are restricted 

 still further to the northward. Only 5 species are known from the 

 North Atlantic, in contrast to the 14 American species and 10 Asiatic 

 species in the North Pacific. 



The tide-pool species are, in a general way, limited in the southern 

 distribution by the summer isotherm of 60° F. The deeper-water 

 forms are not, or but rarely, found in a bottom temperature of 50° F. 

 and are usually found in less than 45° F. This temperature, with the 

 factors governing the vertical distribution, marks the southern limit 

 for the distribution of the deep-water species of the genus. 



Two species of Liparis are known from the Southern Hemisphere. 

 Both are from the cold waters of South America. Liparis antarctia is 

 from Eden Harbor and Liparis steineni from South Georgia. They 

 inhabit an environment similar to that of their northern relatives. 



The distribution of the genus in the Northern and Southern Hemi- 

 spheres bears the same relation to the marine regions of Gill (1875). 

 In the north the genus is distributed from near the middle of the 

 Pararctalia northward and in the south from near the middle of the 

 Notalia southward. 



Asiatic and American species. — The Asiatic and American species 

 are distinct. It can not be said with certainty that any species is 

 found on both sides of the deep Kamchatka Channel. Three species 

 are doubtfully recorded from both sides of this channel. Two imma- 

 ture and poorly preserved specimens from Plover Bay, Siberia, are 

 listed as L. callyodon. Two immature specimens from Petropavlovsk 

 are recorded as L. cyclopus. L. gihhus is recorded from both shores of 

 Bering Sea. Of these species L. callyodon is distinctly a tide-pool spe- 

 cies. The other two descend to deeper water. It appears that there 

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