ZOOLOGICAL NOMENCLATURE. 363 



Naturae/ defined and published certain genera of birds which 

 are additional to those in the twelfth edition of Linnaeus's 

 works, and which are, therefore, of perfectly good authority. 

 But Brisson still adhered to the old mode of designating 

 species by a sentence instead of a word ; and, therefore, while 

 we retain his defined genera, we do not extend the same 

 indulgence to the titles of his species, even when the latter are 

 accidentally binomial in form. For instance, the Perdix rubra 

 of Brisson is the Telrao rufiis of Linnaeus ; therefore, as we in 

 this case retain the generic name of Brisson and the specific 

 name of Linngeus, the correct title of the species would be 

 Perdix rufa.] 



[Generic names not be cancelled in subsequent subdivisions.] 



As the number of known species which form the ground- 

 work of zoological science is always increasing, and our 

 knowledge of their structure becomes more complete, fresh 

 generalizations continually occur to the naturalist, and the 

 number of genera and other groups requiring appellations is 

 ever becoming more extensive. It thus becomes necessary to 

 subdivide the contents of old groups, and to make their 

 definitions continually more restricted. In carrying out this 

 process, it is an act of justice to the original author that this 

 generic name should never be lost sight of ; and it is no less 

 essential to the welfare of the science, that all which is sound 

 in its nomenclature should remain unaltered amid the additions 

 which are continually being made to it. On this ground we 

 recommend the adoption of the following rule : — 



§ 3. A generic name, when once established, should never 

 be cancelled in any subsequent subdivision of the group, but 

 retained in a restricted sense for one of the constituent portions. 



\Generic names to be retained for the typical portion of the 

 old genus.] 



When a genus is subdivided into other genera, the original 

 name should be retained for that portion of it which exhibits in 

 the greatest degree its essential characters as at first defined. 

 Authors frequently indicate this by selecting some one species 

 as a fixed point of reference, which they term the " type of 

 the genus." When they omit doing so, it may still in many 

 cases be correctly inferred that the first species mentioned on 

 their list, if found accurately to agree with their definition, 

 was regarded by them as the type. A specific name, or its 

 synonyms, will also often serve to point out the particular 



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