III. COTTOIDS OF NORTH AMERICA. H 



with a single palaaontological fact which could lead us to suppose that Cottoids 

 have existed there at an epoch prior to the present. On the other hand, we have 

 no reasons to pronounce their total absence in the strata of that continent, since 

 living species are found in its rivers and lakes. 



3. GEOGRAPHICAL DISTRIBUTION. 



The fresh water Cottoids are distributed all over the cold regions of the Temperate 

 Zone of the northern hemisphere, in Asia, in Europe, and in America. They do 

 not generally associate with the Acanthocotti and other allied genera, beyond the 

 arctic circle, around the polar seas, nor do they follow the other representatives of 

 the family in the warm region of their geographical range. 



In Asia, entirely towards the east, in the neighborhood of the Ochotsk Sea, 

 between the 50th and 60th degrees of latitude we find the C. minwtus of Pallas. 

 That illustrious traveler cites the C. gobio in the Lake Baikal, and in the fresh 

 waters of Siberia, which will probably prove to be a new species, if not identical 

 with his G. minutus. 



To the north of Europe, in Scandinavia, we have the C. affinis, Heck. More to 

 the centre and to the east of that continent, in Poland, the G. microstomus, Heck., 

 and still more in a southerly direction, in Hungary, the C. pcecilopus, Heck., but 

 confined to the chain of Carpathian Mountains. 



In the central and western part of Europe, from and including the British Isles, 

 to the chains of the Alps and Pyrenees, a single species is cited, the C. gobio, L. 

 But we know already that Great Britain has peculiar species even if the C. gobio 

 should prove to be an inhabitant. 



Finally, we find on the southern slope of the Alps, in Laggo Maggiore, and in 

 the north of Italy, another species, the C. ferrugineus of Heckel. 



The Cotti of America are almost parallel with those of Europe. In the north of 

 the continent, and near the arctic circle, is found the C. cognatus, Richards. In 

 Greenland, and detached from the continent, but nearly in opposition to G. affinis of 

 northern Europe, we have C. Fabrieii. Southwards, but still in a comparatively 

 eastern range, in the basin of Lake Superior, we meet with two species, the C. 

 Ricluirdsonii, confined to the northern shore and the C. Franldinii inhabiting the 

 southern and eastern shores. Again, in the water emptying into Lake Huron the 

 C. Alvordii, and in the depths of Lake Ontario, C. fwmosus. Along the western slope 

 of the Green Mountains, occurs the C. gobioides and on the eastern slope of the same 

 range, C. boleoidcs. In Massachusetts, New York and Connecticut we have the C. 

 (jracilis, Heck. East of the Alleghany range, are found in Pennsylvania the G. vis- 

 cosus, and in James River (Virginia), the C. meridiotiaUs. West of the Alleghanies 

 we know of the existence of two species, one, C. Bcdrdii, in the northern, the other, 

 C. Wilsonii, in the eastern tributaries of the Ohio. 



The southern limit where Cotti have been observed, is the State of North Caro- 

 lina; but we do not know yet to which species they belong. 



Again, in Lake Ontario we find a species combining such characters as to consti- 



