1^8 MEMOIRS OF 



having demonstrated, for example, all the species 

 which will admit of being arranged in a well- 

 defined genus, all tlie genera which may be 

 placed in a well-defined family, to leav^e out one 

 or several isolated species or genera, which are 

 not attached to others in a natural manner ; 

 preferring the honest avowal of these irregu- 

 larities, if we may be allowed to call them so, to 

 those errors which must arise from leavincc these 

 species, and anomalous genera, in a series, the 

 characters of which they do not embrace." 



The first great division of Fishes treated of by 

 M. Cuvier, and with which the second volume 

 commences, is that of the Acanthopterygii, or 

 fishes with spinous rays to their fins ; and fore- 

 most amongst these, is the numerous family of 

 the Perches, or Percoides, which occupies the 

 two succeeding volumes. The fourth volume 

 contains the family of the Joues Cuirassees, many 

 of which, and especially those of the tropical 

 seas, present themselves under extraordinary 

 and exaggerated forms, and to which belong 

 the beautiful little sticklebacks of our running 

 streams. The fifth volume embraces the Scien- 

 oides ; the sixth, the Sparoides, and the Menides ; 

 the seventh, the Squammipennes, and the Pha- 

 ryngiens Labyrinthiformes j and the eighth and 



