ZOOLOGY. 



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24. Perca. Perch. Bodjj covered with rough scales ; edges 



of the gill-covers serrated ; gill-membrane seven rayed ; 

 dorsal fins two, the first spiny ^ the second sojt. 



25, Holocentrus. Gill-covers serrated, spinous, scaly ; 

 scales hard and rough ; in other respects agreeing with 

 the genus Perca. 



^6. Bodianus. Gill-govers and habits like the last genus ; 

 scales smooth. 



17. Scomber. M\ckrel. Head compressed, smooth ; gilt- 

 membrane.sQYen. rayed ; several small, spurious, prickly 

 finsy between the dorsal Jin and the tail. 



Though not a very numerous family, the individuals of 

 some of the species are almost without number, particularly the 

 common Mackrel, which visits our coasts periodically in 

 such immense shoals, as to aiiord employment to a very large 

 part of the laoouring population, resident on the coasts 

 where these fish aio caught ; they appear early in the spring 

 and continue on the coasts during most of the summer 

 months ; the gei.era'ly r^^ceived opinion is, that the Mackrel 

 quits our seas during winter ; but this is not satisfactorily 

 proved ; perhaps after spawning, they only quit the vicinity 

 of our shores, and retire to deep water, as repeated instances 

 have occurred of individual fshes being fished up from deep 

 water during ihe Vv'inter season ; in some places these fish are 

 caught by the hook and line, and in others, in nets of very 

 large dinicnstor s ; all the species are gregarious, emit a phos- 

 phoric light, and may be eaten with safety. 



