(iO THE FRESH- WATER FISHES OF EUROPE. 



be affected by varying external circumstances, and by internal impressions. 

 In the breeding- season the upper parts of the body are yellowish-grey or 

 green, marbled with brown. The face is generally darker than the body. 

 The under side of the body is paler, and free from spots. The pectoral and 

 ventral fins are pale-yellow or greenish, often without spots. The anal 

 fin is sometimes colourless, sometimes bluish, with variable black spots, 

 often becoming a black band. The first dorsal fin is the most variable in 

 colour ; it often has a broad black band at the base, and the upper part 

 of the fin shows brilliant metallic tints margined 'externally with white. 

 The second dorsal fin is transparent grey, with horizontal lines of brown 

 spots. The iris is yellow. 



In the breeding period the body and fins often become covered with 

 little tubercles. The males are usually the thinner fish. The females are 

 most easily recognised by the blunter snout and broader urogenital papilla. 

 They have two large ovaries, and a smaller air-bladder. The male sexual 

 organ varies considerably among the Gobies. The common size of the fish 

 does not exceed a length of three inches, though larger and smaller specimens 

 have been captured. This species commonly hides under stones, to which the 

 female attaches her eggs. They are stated to be spindle-shaped, connected 

 in a row, and to float about on the surface of the waters, and develop in June. 



The fish is eaten, and regarded as well flavoured. It is abundant in 

 all the canals and small streams of Lornbardy, in the Rivers Isonzo and 

 Treviso, and it is found in the Lakes of Garda and Maggiore. The Lombards 

 term it Bottola and Bottina, and the Tuscans name it Ghizzo. 



This fish was named by Cuvier Gobiuft ftuviatilis. 



The species includes several varieties. Three of these have been defined 

 by Professor Canestrini as Gobius avernensis, 1 D. 6, 2 D. 1/12 13, A. 1/8 9, 

 from the Arno ; Gobius panizztz, 1 D. 5, 2 D. 1/8, A. 1/7, from Lago di 

 Garda ; Gobius punctatissimus, 1 D. 6 8, 2 D. 1/7 8, A. 1/7 8, V. 1/5, 

 P. 1/16, C. 13. 



The first of these varieties is distinguished from the type chiefly by 

 the more elongated form of body, the more pointed form of snout, and 

 especially by having about forty-seven scales in a longitudinal row on the 

 side. But Fatio regards this species as so variable that it would be easy to 

 select individuals to which distinctive names might be as well applied as 

 those which have been distinguished as species by the Italian ichthyologist; 

 and although we have no personal knowledge of the variation of this Goby 

 in Italy, the characters assigned to Canestrini's types seem better to accord 

 with varieties than species, though in this matter our judgment is necessarily 

 governed by the relative persistence of characters. 



