302 Mr J. D. Dana on Nomenclature in Natural History. 



manner as possible, to secure more easy reference, and a 

 more extended circulation ; but they would strongly urge the 

 perusal of the whole Report in the volume of the British 

 Association for 1842, (pp. 105 to 121), in which numerous 

 examples are given, by way of illustration, and the reasons 

 for adopting the various laws are presented in a forcible and 

 lucid manner.* 



I. LAW OF PRIORITY, WITH ITS LIMITATIONS. 



§ 1. The name originally given to a group or species by 

 its founder, should be retained, to the exclusion of all subse- 

 quent synonyms. 



The systematic nomenclature having originated with Lin- 

 naeus, this law is not to extend to the writings of more ancient 

 authors. 



§ 2. In the progress of science it often becomes necessary 

 to restrict or extend the characteristics of a genus, or sub- 

 divide a genus into several genera. The following principles 

 bearing upon the above law, should be adopted in making 

 such changes. 



a. When several smaller genera are united in one, the 

 name of the earliest, if otherwise unobjectionable, should be 

 selected for the name of the whole group. 



h. When a genus is subdivided, the original generic name 

 should not be cancelled, but should be retained for that por- 

 tion of it which was considered typical by the author : or if 

 the evidence as to the original type is not clear and indisput- 

 able, it may be given to any portion of it. 



c, .When two authors define and name the same genus, 

 both making it exactly of the same extent^ the latter name should 

 be cancelled in toto, and not retained in a modified sense : 

 except, when its type (as laid down by its author) belongs to 

 a different section of the genus from that of the other name, 

 and both sections are elevated to genera. 



For example — the genus Monaulus of Vieillot (1816), is a 

 precise equivalent to the Lophophorus of Temminck (1813), 

 both authors having adopted the same species as their type ; 



* The Report following, is given, as adopted with some modifications^ 

 by the Association of American Geologists and Naturalists, 1845. 



