66 
LECTURE VIIL 
Among the Thoracic Fishes rank all the kind^ 
of Perches^ forming the Linnaean genus Perea, 
They have sharp teeth, scaly and serrated gill- 
covers, and a back-fm with the fore-part furnished 
with spiny rays, and the back part with soft ones , 
and the scales in most species are hard and rough. 
The common Perch is an elegant fish, of an olive 
brown, marked by five or six dusky transverse bars, 
and is found in most parts of Europe. 
Very strongly allied to the genus Perea are 
the several lately instituted genera of Holocentrus 
Sciana and some others. 
The Fishes of the Mackrel tribe belong to a 
genus called Scomber, and are distinguished by 
their oblong body, furnished above and below the 
back-part near the tail, with several small or spu- 
rious fins ; in some species also the lateral line or 
middle longitudinal division of the Fish is fur- 
nished with a series of strong and broad scales^ 
The common Mackrel is universally known, and 
is certainly one of the most beautiful of the Eu- 
ropean Fishes. Its celebrated migrations, so well 
detailed in the entertaining work of Mr. Pennant, 
begin now to be greatly called in question, and it 
is rather supposed that the glittering myriads 
