CHa rT ER. F- 
ON THE FRESH WATER COTTOIDS IN GENERAL. 
§ 1. ZooLocicaL CONSIDERATIONS. 
For nearly a century a single species of fresh water Cottoid was known in 
Europe, a small fish very common there in rivers and lakes, and whose obtuse 
form and flattened head (which is broader than the body) brought it to the notice 
of every one. A long time before ichthyologists gave it a systematic name, many 
nations, including the French, English, Danes, Swedes, Germans, Italians, Hunga- 
rians, and Russians, had assigned to it a vulgar one in allusion to the breadth of 
the head, which in fact is the chief character of the genus; and this generic cha- 
racter, so clear and so precise, involved the apparent uniformity among the species. 
For this reason the species were not at first distinguished, being referred from 
vague recollection, and from the opinion of the people, to the C. gobio of Artedi 
and Linnzus. Thus the same species was believed to inhabit the fresh waters of 
nearly the whole ancient hemisphere, in Europe from Sweden to Italy, and from 
France to Siberia. Cuvier, however, after having enumerated the localities which 
the C. gobio inhabits, adds: “ But perhaps it would be necessary to see together 
and to compare individuals from countries so remote from each other, in order to 
ascertain that they do not present some differences which have escaped isolated 
observers.”’ From this moment suspicion began to be entertained: this was to be 
the prelude to new researches. 
Thus eight years after these lines were written, Mr. Heckel,” taking up the 
study of the Cottoids, distinguished three new European species; namely, his Cottus 
affinis, microstomus, and peecilopus. The first inhabits Scandinavia, dnd had been 
referred by Eckstrém® to Cottus gobio, and in fact it is the fish that Artedi and 
Linneus had in view, though not specially, since they gave to their species, as 
geographical range, the whole continent of Europe. Cottus microstomus is from the 
vicinity of Cracow, and C. pecilopus from the Carpathians in Upper Hungary. 
Some time afterwards the same naturalist wrote to Ch. L. Bonaparte that C. 
gobio from Italy was a distinct species, and gives to it the name of C. ferrugineus.* 
1 Histoire Naturelle des Poissons, iv., 1829, 8vo., p. 150; 4to. ed., p. 110. 
* Ichthyologische Beitriige, in Ann. des Wien. Mus., vol. ii., 1837, p. 150. 
3 Fiskarne i Mérk6 Skirgard, p. 139. 
* Catalogo Metodico dei Pesci Europei di Carlo L. Principe Bonaparte, Napoli, 1846. 
