CHAPTER I. 



ON THE FRESH WATER COTTOIDS IN GENERAL. 



1. ZOOLOGICAL 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 Linnjeus. 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." 1 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, 2 taking up the 

 study of the Cottoids, distinguished three new European species; namely, his Coitus 

 affinis, microstomus, and pozcilopus. The first inhabits Scandinavia, and had been 

 referred by Eckstrom 3 to Coitus gobio, and in fact it is the fish that Artedi and 

 Linnoous had in view, though not specially, since they gave to their species, as 

 geographical range, the whole continent of Europe. Coitus microstomus is from the 

 vicinity of Cracow, and C. paedJopus 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.* 



Histoire Naturelle des Poissons, iv., 1829, 8vo., p. 150; 4to. cd., p. 110. 

 Ichthyologische Beitriige, in Ann. des Wien. Mus., vol. ii., 1837, p. 150. 

 Fiskarne i Morko Skargard, p. 139. 

 Catalogo Metodico dci Pesci Europei di Carlo L. Principr Bonaparte, Napoli, 1846. 



