On the Scales of Fishes. 253 



lateral spot are somewhat different from the others in some 

 particulars beyond the colour. 



Glupea pilchardus. — In all the examples examined there 

 has been found a peculiarity of which there has not been seen 

 anything like it in other sorts of fish, but the nature of 

 which appears exceedingly obscure. It is, that below the 

 lower portion of many of the scales, and not of all, and not 

 always in exactly the same place, there has been a separate 

 very small scale — one or more, even to three or four. They 

 resemble in a considerable degree, both in size and figure, as 

 well as in organization, the scales of the trout ; and they never 

 occur behind the middle of the covering scale, while the latter 

 are as firmly fixed as any of the others. One of these small 

 scales only was seen to' have points at its edge. 



Gluper harengus, Engraulis encrasicholus, Alosa finta; A. 

 squ amopinnata, miiri. 



Serranus cabrilla, Sebastes norvegicus. 



Esox lucius. — A peculiarity is, that the lobes of the dona- 

 tions at the inner border on the left overlap each other. 



Belona vulgaris. — Although the bones of this fish are natu- 

 rally green, the scales are not so, except from the colour of 

 the skin that covers them. 



Pleuronectes punctatus, Rhombus vulgaris. 



Salmo trutta. — The scales, as in all of this tribe, are small 

 and thin, with a shining pearly look ; the cause of which is 

 not in the scale itself, but it proceeds from a bright deposit or 

 lining on the lower surface, and may be easily removed. Such 

 is the case also with some other fishes, and in the young 

 salmon it appears to be formed at that period of its growth 

 when a migration to salt water has become necessary to its 

 well-being. The scales of 8. trutta are attached chiefly, if not 

 solely, at the disk, and that not firmly. 8. Fario. 



Scomber vulgaris, 8c. scriptus, Nobis, Ausonia Cuvierii. 



Brama Itcdi. — In the axilla of the pectoral fin is an arrange- 

 ment of scales formed in the likeness of a moveable cover, and 

 which in size and shape differ from those of the rest of the body. 



Naucratcs ductor. 



Among the fishes of the genus Gadus the scales are small, 

 and of the simplest form, which does not require particular 

 remark. 



Several kinds of fishes, also, from the Upper or White Nile, 

 have been studied, with the same object, of observing the 

 peculiarities of their scales ; but in this they do not differ from 

 our common kinds. 



