CHAPTER I. 

 ON THE FRESH WATER COTTOIDS IN GENERAL. 



§ 1. Zoological Considerations. 



For nearly a century a single sjDecies 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. gohio of Artedi 

 and Linnfeus. 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 G. gohio 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, microstonms, and poecilopus. The first inhabits Scandinavia, and had been 

 referred by Eckstrom'^ to Cottxis gohio, and in fact it is the fish that Artedi and 

 Linna^ius 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 G. xxxcihpus from the Carpathians in Upper Hungary. 



Some time afterwards the same naturalist wrote to Ch. L. Bonaparte that G. 

 gohio from Italy was a distinct species, and gives to it the name of C. ferrugineus} 



» 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. 



= Fiskarne i Morkb Skargard, p. 139. 



* Catalogo Metodico dei Pesci Europei di Carlo L. Piindpe Bonaparte, Napoli, 1846. 



