REVISION OF THE FISH FAMILY LIPARIDAE 23 



are either monotypic or composed of a few species and confined to 

 the North Pacific. Nedoliparis, consisting of a single pelagic species, 

 ranges widely over the North Pacific. Polypera consists of three 

 shallow-water species distributed along the shores of British Columbia, 

 Aleutian, and Kurile Islands. Temnocora consists of a single species 

 from Bering Sea. Crystallichthys is represented by two species 

 from Bering Sea and Pacific Ocean off Kamchatka. Crystallias 

 is a monotypic Japanese genus. Gyrinichihys consists of a single 

 Bering Sea species. Elassodiscus and AcantJioliparis are represented 

 by a single species from southeast of Kamchatka. RMnoliparis con- 

 sists of two species which are distributed from California through 

 Bering Sea to Japan. 



Species. — It is generally said that deep-sea fishes are more cos- 

 mopolitan in their distribution than shallow-water forms. It is 

 assumed that the environment of the deep sea is quite uniform for 

 each depth and that the species will not be prevented from spread- 

 ing widely over the bottom of the ocean Many of the species 

 have a great vertical range which would enable them to migrate 

 more readily. A great vertical range suggests that either the en- 

 vironment changes vary gradually with depth or that the species 

 are adapted to a varied environment. 



At the present time there appears to be a tendency to believe 

 that deep-sea fishes are not so widely distributed as we have been 

 accustomed to suppose. This view is substantiated by the deep- 

 sea Liparids. These species appear to be little more cosmopolitan 

 than their relatives of the shallow water. In considering this state- 

 ment it should be borne in mind that we know little about these 

 fishes. The deep-sea species are sluggish and, with but one or a few 

 exceptions, live upon or near to the bottom. The majority of the 

 species are known from but a single locality or region. None are 

 common to the Atlantic and Pacific Oceans or to the north and tropi- 

 cal Pacific. The majority of the American and Japanese species 

 are distinct. Only one species of RMnoliparis and two species of 

 Careproctus are found in both the American and Japanese faunas. 



The maximum range in latitude for the deep-sea and shallow- 

 water species is about the same. A few species of Liparis, Care^ 

 proctus, Paraliparis, and RMnoliparis range through about 20° of 

 latitude. The majority of the species have a more restricted range. 

 The distribution of the species of Liparis, Careproctus, and Parali- 

 paris appears to be quite comparable. This similarity may disappear 

 when we come to know the deep-sea species better. 



The giant species of the family are confined mainly to the north- 

 west Pacific from Bering Sea through the Okhotsk Sea to northern 

 Japan. This is especially true of the large species of Liparis, Care- 

 proctus, and CrystallicMhys. The largest species of Paraliparis, a 



