40 AMERICAN ANGLER'S BOOK. 



interior of the mouth and throat was thickly studded with 

 hard, crushing teeth. 



Next to the Placoidal order, and before they had dimin- 

 ished in number, came the Ganoids, whose covering consisted 

 of a nearly continuous armor of hard bone with an enamelled 

 surface. One of the few representatives of this order, known 

 to us, is the " Lepidosteus" (the Gar-fish of the South and 

 West), whose coat of mail appears to be made of diamond-' 

 shaped pieces closely joined with sutures between. Hugh 

 Miller says, " with the Old Bed Sandstone, the Ganoids were 

 ushered upon the scene in amazing abundance, and for untold 

 ages, comprising mayhap, millions of years; the entirelchthyic 

 class consisted, so far as is yet known, of but these two 

 orders (Placoids and Ganoids). During the time of the Old 

 Eed Sandstone, of the Carboniferous, of the Permean, of the 

 Triassic, and of the Oolitic systems, all fishes apparently as 

 numerous as they now are, were comprised in the Ganoidal 

 and Placoidal orders. At length during the ages of the 

 Chalk, the Cycloids and Ctenoids were ushered in, and 

 gradually developed in (Creation until the human period, in 

 which time they seem to have reached their culminating 

 point, and now many times exceed in number all other 

 fishes." 



The "Ctenoids," here mentioned by Miller, as the third' in 

 order of Creation, is one of the four orders erected by Agassiz, 

 and comprise all of those fishes, the free edges of whose 

 scales are serrated or pectinated like the teeth of a comb. To 

 this order belong the whole family of Perch, and other 

 families which have sharp spinous dorsal fins. Amongst the 

 Cycloids, are contained all those whose scales have smooth 

 continuous margins; these are generally or entirely soft- 

 finned fish, as the salmon, shad, herring, carp, chub, &c. 



In describing the fishes of the earlier periods, Hugh Miller 



