Dispersion of Fresh-water Fishes 291 



of North America, north of the Tropic of Cancer, these repre- 

 senting thirty-four of the natural families. As to their habits, 

 we can divide these species rather roughly into the four cate- 

 gories proposed by Prof. Cope, or, as we may call them, 



(1) Lowland fishes; as the bowfin,* pirate-perch, f large- 

 mouthed black bass.J sunfishes, and some catfishes. 



(2) Channel-fishes; as the channel catfish, the mooneye, || 

 garpike,l[ buffalo-fishes,** and drum. ft 



(3) Upland fishes; as many of the darters, shiners, and 

 suckers, and the small-mouthed black bass.JJ 



(4) Mountain-fishes; as the brook trout and many of the 

 darters and minnows. 



To these we may add the more or less distinct classes of (5) 

 lake fishes, inhabiting only waters which are deep, clear, and 

 cold, as the various species of whitefish and the Great Lake 

 trout ; || || (6) anadromous fishes, or those which run up from 

 the sea to spawn in fresh waters, as the salmon, 111 sturgeon,*** 

 shad,ftt and striped bass;||J (7) catadromous fishes, like the 

 eel, which pass down to spawn in the sea; and (8) brackish- 

 water fishes, which thrive best in the debatable waters of the 

 river-mouths, as most of the sticklebacks and the killifishes. 



As regards the range of species, we have every possible gra- 

 dation from those which seem to be confined to a single river, 

 and are rare even in their restricted habitat, to those which are 



is about 360. The fauna of India, south of the Himalayas, is much more 

 extensive, numbering 625 species. This latter fauna bears little resemblance 

 to that of North America, being wholly tropical in its character. 



* Amia calva Linnaeus. 



f Aphredoderus sayanus Gilliams. 



J Micropterus salmoides Lace"pede. 



Ictalurus punctatus Rafinesque. 



|| Hiodon tergisus Le Sueur. 



^f Lepisosteus osseus Linnaeus. 



** Ictiobus bubalus, cyprinella, etc. 



ft Aplodinotus grunniens Rafinesque. 



JJ Micropterus dolomieu Lac6pede. 



Coregonus clupeiformis , Argyrosomus artedi, etc. 



UK Cristivomer namaycush Walbaum. 



fH Salmo salar Linnaeus. 



**.* Acipenser sturio and other species. 



ttt Alosa sapidissima Wilson. 



|JJ Roccus lineatus Bloch. 



Anguilla chrysypa Raf. 



