﻿LAWS OF NOMENCLATURE. 



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than a thrush, should be called Tyrannus intrepid us. 

 Names, on the other hand, derived from the general or 

 partial colouring of the plumage, are appropriate at all 

 times ; and, together with such others as express the 

 essential specific character, are perfectly unexception- 

 able. Names, also, which express the local haunts of 

 different species, although not so good, as being less in- 

 telligible, are not to be rejected, as Alauda pratensis, 

 Anthus aquaticus, &c. 



(200.) A genus or sub-genus can never be admitted 

 into a circle which has been demonstrated to be com- 

 plete, without its rank and station has been analysed, 

 and is made known ; in other words, it must be proved, 

 in the first place, to be natural. This rule is of course 

 only applicable to such groups as have been completely 

 analysed, and where the system followed is a natural 

 one. We have said so much on this head in another 

 volume, that recapitulation is here unnecessary. We 

 have been inundated, particularly from France and Ger- 

 many, with (i new genera," as they are termed, which 

 their inventors can give no other reason for making, 

 than that they fancy them to be so. It is really time 

 that we called for some better reason than this, more 

 especially in ornithology; we must be pardoned, therefore, 

 in future, for not giving currency to such divisions, un- 

 less they are first shown to be natural. 



(201.) A genus should possess at least three positive 

 and discriminating characters, but a sub-genus usually 

 possesses only one. — It is totally impossible to lay 

 down any positive rules by which either of these groups 

 can be distinguished ; for they vary in almost every 

 family. The above conclusion, however, is the result of 

 much study ; and we must leave those who are disposed 

 to verify its truth among some of the best known groups. 

 It is quite obvious, however, that a sub-genus can never 

 be known from an aberrant or osculent species, until the 

 circle to which it belongs has been analysed ; and there- 

 fore it becomes extremely desirable, at least in a na- 

 tural classification, not to mix up imaginary divisions 

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