54 HIGH SCHOOL ZOOLOGY. 



5. The genei'Jc, specific, and varietal names ai'e genei^ally 

 Latin or latinized Greek words in form, the generic name 

 being always a noun, and the specific and varietal names either 

 adjectives agreeing thei-ewith, or nouns in apposition. Although 

 these names often refer to some characteristic of the form de- 

 signated, yet this is not always the case, and there is no definite 

 understanding among zoologists as to the principle on which 

 such names shall be selected. For example the name Amiurus 

 has been formed to express the fact that the tail-fin is not notch- 

 ed in this genus, whereas the name of the most nearly allied 

 genus Ictalurus or Ichthaelurus, whei'e the tail is notched, is 

 simply a Greek translation of Catfish. Again the specific 

 adjectival name nebulosus is formed to express the peculiar 

 clouded colouration of our Catfish, while its synonym catus, a 

 noun in apposition with Amiurus is another reference to its 

 common name; further, the varietal names marmoratus, livldus, 

 cuprevs are adjectives expi*essing some colour-peculiarity of 

 the forms designated, while the specific name of our great fork- 

 tailed Catfish /. lacustris refers to its occurrence in large bodies 

 of water. 



6. The species last referred to attains a large size, reaching 

 occasionally a weight of 100 pounds; it is abundant in the 

 Great Lakes and St. Lawrence, and is much used for food. 

 Another allied form the Channel Cat (/. punctatus) is found in 

 the channels of the large streams but does not reach the size 

 of the gi'eat Catfish. In contrast to these are several species 

 of Noturus — Stone-Cats, (Fig. 20) which are rarely more than 

 4 or 5 inches in length, have the habit of lurking under stones, 

 and are marked by the long adipose fin which is almost con- 

 tinuous with the tail-fin. 



7. These three genera are the representatives in Canada of 

 a very large group or " family " of Fishes, the members of which 

 abound in the fresh waters of the tropics of the old and new 

 world, but ai-e only represented in Europe by one species the 



