228 FAUNA OF SHROPSHIRE. 



and balance the body, but the flattened tail is the chief 

 instrument of propulsion. The fins on each side of the 

 breast are called the pectoral fins, those on the back the 

 dorsal fins, on the belly ventral fins, the one behind the vent 

 anal fin, and the tail the caudal fin. The paired fins 

 pectoral and ventral are those which correspond to the fore 

 and hind limbs of the higher vertebrates. The body is 

 covered with slime secreted by glands on the flanks; their 

 openings form a distinct mark along the sides, known as 

 the lateral line. Respiration is performed by gills which are 

 arranged on bony arches, and the heart has only two 

 chambers. There are no eyelids or external ears. The teeth 

 are generally numerous and pointed, and occur on the palate 

 and tongue as well as the jaws ; they serve only for prehen- 

 sion. Of the twenty-eight species of Fishes here enumerated, 

 twenty-two are resident, the rest migratory. The names of 

 resident species are printed in capitals; migrants in small type. 



PERCH. The poet Pope speaks of this handsome fish as 

 Pcrca fluviatilis. " The bright-eyed Perch, with fins of 



Tyrian dye." It is common in pools 

 . and quiet parts of rivers that are more or less sluggish, 

 and for its bold biting habits it is beloved by youthful 

 anglers. In large pools it often attains a considerable 

 size, and, as it is a voracious fish, it is frequently taken 

 on live and spinning baits intended for pike. It spawns 

 about April, and is in best condition for the table in the 

 winter. The Perch of this decade is said to have de- 

 generated as much as the trout. In some streams it has 

 almost died out, and although reckoned one of the hardi- 

 est of fishes,, it has been found, by fish culturists, to be 

 about the most difficult to bring up by hand. The 

 Severn is fairly well stocked with Perch ; the more so 



