196 BRITISH FRESHWATER FISHES 



the caudal fin, and usually more than the length of 

 the head, which is one-fifth to one-fourth of the 

 same distance. The small mouth is terminal or 

 nearly so, and has the cleft more or less oblique, 

 sometimes nearly horizontal ; the pharyngeal teeth 

 are compressed, hooked, entire, or feebly pectinated, 

 arranged in a single series, five or six on each side. 

 The scales are rather large, varying in number from 

 forty to forty-six in the lateral line, whilst there are 

 from seven to nine longitudinal series between the 



a. t, 



FIG. 2O. Lower pharyngeals of Rudd (a) and Roach (b), showing the 

 difference in form and number of the teeth (after Fatio). 



origin of the dorsal fin and the lateral line and three 

 to four and a half from the latter to the base of the 

 pelvic fins. 



The dorsal fin originates above the end of base 

 of the pelvic fins, is composed of three graduated 

 simple rays and nine to eleven branched ones, is 

 rather elevated, and has the free edge concave ; the 

 anal fin has three simple and nine to twelve 

 branched rays, but its base is shorter than that of 

 the dorsal. 



The Roach is a silvery white fish, with the back 

 greenish, and with the lower fins usually tinged with 



