CHAPTER VI 

 EVIDENCES FROM CLASSIFICATION 



THE PRINCIPLES OF CLASSIFICATION 1 

 A. F. SHULL 



The International Code. — Some of the essential features of the 

 International Code are as follows. The first name proposed for a 

 genus or species prevails on the condition that it was published and 

 accompanied by an adequate description, definition or indication, and 

 that the author has applied the principles of binomial nomenclature. 

 This is the so-called law of priority. The tenth edition of the Sytema 

 Naturae of Linnaeus is the basis of the nomenclature. The author of 

 a genus or species is the person who first publishes the same in connec- 

 tion with a definition, indication or description, and his name in full 

 or abbreviated is given with the name; thus, Bascanlan anthonyi 

 Stejneger. In citations the generic name of an animal is written with 

 a capital letter, the specific and subspecific name without initial 

 capital letter. The name of the author follows the specific name 

 (or subspecific name if there is one) without intervening punctuation. 

 If a species is transferred to a genus other than the one under which 

 it was first described, or if the name of a genus is changed, the author's 

 name is included in parentheses. For example, Bascanion anthonyi 

 Stejneger should now be written Coluber anthonyi (Stejneger), the ge- 

 neric name of this snake having been changed. One species constitutes 

 the type of the genus; that is, it is formally designated as typical of 

 the genus. One genus constitutes the type of the subfamily (when a 

 subfamily exists), and one genus forms the type of the family. The 

 type is indicated by the describer or if not indicated by him is fixed 

 by another author. The name of a subfamily is formed by adding 

 the ending -inae, and the name of a family by adding -idae to the root 

 of the name of the type genus. For example, Colubrinae and Colubri- 

 dae are the subfamily and family of snakes of which Coluber is the 

 type genus. 



The basis of classification.— Early systematists largely employed 

 superficial characters to differentiate and classify animals, and their 



1 From A. F. Shull, Principles of Animal Biology (copyright iq2o). Used by 

 special permission of The McGraw-Hill Book Company 



93 



