1 80 O UTLINES OF ICHTH YOL OGY. 



Grayling. (Thymallus vulgaris.) 

 Fresh Water Herrings. (Coregoni.) 



(Four species or varieties.) 



ORDER III. 

 Soft-finned Fish having lower arms. 



Family i. Cod GADID^:. 

 Species. 



Burbot, or Eel-pout. (Lota vulgaris.) 



ORDER IV. 

 Soft-Finned Fish lacking ventral fins. 



Family i. Eels MUR^NID^E. 

 Species. 



Sharp-nosed Eel. (Anguilla acutirostris.} 

 Broad-nosed Eel. (Anguilla latirostris.} 

 Snig. {Anguilla mediorostris.} 



2ND SERIES. 

 CARTILAGINOUS FISH. 



ORDER II. 



Fish with Fixed Gills. 

 Family i. Fish with mouth formed in a sucker. 



CYCLOSTOMATA. 

 Species. 



Lamprey, or Sea Lamprey. (Petromyzon marinus.) 

 Lampern, or River Lamprey. (Petromyzon fluviatilis^ 

 Fringed-lipped Lampern. (Petromyzon PlaiieH.) 



To give a practical example of this classifica- 

 tion : The Common or River Perch is a species of 

 the genus Perca, of the Family of the Percida, of 

 the Order Acanthropterygii, belonging to the True 

 or Bony series of fish ; or, in other words, is the 

 first Species, of the first Genus, of the first Family, 

 of the first Order, of the first Series. 



