VERTEBRATA. PISCES. 



a. THORACIC* PERCHES. 



Perca, the Perch. 



THE PERCH (Perca Fluviatilis). 



The true Perches, inhabitants of calm lakes and 

 smoothly flowing rivers, have the fore gill-cover 

 toothed, and the gill-cover spined; the tongue smooth 

 and free ; the gills have seven rays ; the ventral fins 

 have five soft rays; the dorsal fins are two, large 

 and strong, with stout spines ; the teeth very small 

 and close, resembling the pile of velvet ; scales large, 

 and toothed at the edge. The colours are generally 



* From thorax^ the chest. 



