CONCLUSIONS. 95 



nessee, and Cumberland, and Alburnops microstomus in the James, Eoa- 

 noke, Kentucky, Cumberland, and Clinch. 



XXIV. Certain species have a wide east and west range, without 

 api)arent regard to the courses of the rivers, but are bounded on either 

 the nortli or the south by parallels of latitude. 



Eucalia inconstans occurs from Western New York to Kansas and 

 norrhward, but it is never found southward of a line passing about fifty 

 miles souih of Lake Erie. Pcrcopsis f/uttatns has a like range, but its 

 southern boundary is in the Potomac and Ohio. Lota lacusiris is simi- 

 larly circumscribed, but ranges farther to the east. The three species 

 of Lyihrurus have each a belt of latitude: L. cyanocephalns belonging 

 to the Great Lakes and Ui)per Missi&sippi ; L. (Ux)h('mms to the Ohio 

 and the Potomac; X, ardens to the Eoanoke, James, and Cumberland. 

 The three species of Hyodon are similarly arranged. 



XXV. Certain species have a i)eculiar northern and eastern range, 

 occuriing in the waters of the Upper Mississippi, in the headwaters of 

 the Illinois, Wabash, and Scioto, thence through the Great Lakes to 

 Xew England, thence to South Carolina on the eastern slope of the 

 Alleghanies. Such species are Eupomotis aureus^ Perca americana, and 

 Aiiiiurus catufs. 



XX VL Certain species have a peculiar northern and western range, 

 occurring in the Middle States and in the Great Lakes, and usually 

 southwriid in the east to some point in Virginia or Xorth Carolina, 

 ceasing in the same latitude on both sides of the Alleghanies, but ex- 

 tending southwestward through the Mississippi Valley to the Gulf of 

 Mexico. Among these may be mentioned Lnxilus comutus, Notemigonim 

 chrysoleucuN, Ambloplites riipestris, Apomotis cyanellus. The last-named 

 species, however, scarcely ranges east of the Alleghanies. 



XXVI I. Certain species have a wide range north and south, either 

 east or west of the Alleghanies, but do not cross that chain. Of these 

 may be mentioned Lepiopomits auritus, Enneacanthus ohesus, Esox rcticu- 

 latii.s, etc., on the east, and Ilaploulonohis grunniens, Hyodon ter-yisus, 

 Noturus iniurus, Noturnn sialis, etc., on the west. 



XXVliL The distribution of fresh-water fishes is dependent (a) on 

 fresh-water communication ; {b) on character of stream, i. e., of water — as 

 to pui ' ty, depth, rapidity, vegetable growth, etc. ; (c) on the character of 

 the river-bed ; {d)on climate, as determined by latitude and by elevation 

 above the sea; and (e) finally on various unknown factors arising from 

 the natuio or past history of the species in question, and from the geo- 

 logical historv of the rivers. 



