Genera and Subgenera should be established. 387 



simply because it was while examining our genera of British 

 birds, as adopted by most ornithologists of the present day, 

 that I was led to notice their great inequality in respect to 

 the value of the characters on which they rested. As one 

 instance in point, I may mention a small group separated by 

 Meyer from Emberiza of Linnaeus, under the name of Plec- 

 trophanes, and by Vieillot under that of Passerina. The 

 original genus Emberiza, of which our common bunting is 

 the type, may, perhaps, be considered, on the whole, as a 

 strictly natural one; and as forming a group of equal value 

 with those of ^lauda and Pringilla, two allied genera, be- 

 longing to the same family. Plectrophanes agrees with 

 Emberiza in its most essential characters, but, at the same 

 time, offers one or two peculiarities, by which it is distinguished 

 from the more typical species of that genus. On these 

 grounds, taken in connection with some slight difference of 

 habits, it deserves to be considered as a peculiar group ; but 

 surely we must allow that it ought to rank subordinate to 

 Emberiza itself, inasmuch as its characters are of less value 

 than those which serve to connect all the species originally 

 comprised in that genus. 



As offering examples to the purpose in another order, I may 

 mention the Linnaean genera Tetrao and Perdix. These groups 

 likewise are strictly natural ones, and clearly of the same value. 

 Each, however, includes several smaller and more subordinate 

 groups, among which we may select Lagopus and Coturnix, as 

 well known and not the least conspicuous. The former bears 

 the same relation to Tetrao that the latter does to Perdix, re- 

 sembling*it in its general, but differing from it in one or two 

 particular, characters. Now, however we may assert (and, per- 

 haps, the assertion is not more than the truth) that the above 

 four groups are all equally natural, it surely never can be said 

 that they are all of equal value ; that is to say, that jLagopus 

 has not many more characters in common with Tetrao than 

 it has with Perdix, and Coturnix with Perdix than it has 

 with Tetrao. How, then, with any show of regard to the 

 true principles of classification, can we consider them as so 

 many equally distinct genera in the family of Tetraonidas ? * 



We find a third example offered us in the genus ^'rdea, 

 among the Grallatores. This group, equally natural with 

 those last alluded to, rests in point of value on much the 

 same grounds with Ciconia and Platalea, and some other 

 genera belonging to the family of ^rdeidae. It comprises, 

 however, as in the former instances, within itself several 



* See Zoological Journal, vol. ii. p. 402., where they appear to be so 

 considered. 



c c 2 



