CHAPTER VIII 
EVIDENCES FROM CLASSIFICATION 
THE PRINCIPLES OF CLASSIFICATION* 
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, definite or indication, and 
that the author has applied the principles of binomial nomenclature. 
This is the so-called Jaw 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, Bascanian 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 
«From A. F. Shull, Principles of Animal Biology (copyright 1920). Used by 
special permission of The McGraw-Hill Book Company. 
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