Vol. XXXV.] 80 



A fast and binding rule can, however, not be drawn 

 for the separation and limitation of genera, and in some 

 cases colour-pattern is of unusual interest. This is beauti- 

 fully illustrated by tbe Cuckoos of the genus Phcenicophaes, 

 which Mr. Lowe brought to our notice. Here we have at 

 least a dozen forms of birds which are practically alike, but 

 differ in the shape of the nostrils ! Because this is a 

 "structural" character they were separated into 4 or 5 

 " genera." To this I do, of course, not agree, but it is not 

 quite fair to say that they belong to the same genus because 

 they have the same colour, as they agree in the structure of 

 all parts of their body*; common-sense must be used, and 

 a slightly different shaped nostril alone must not be taken 

 as a " generic character/^ unless accompanied by other 

 peculiarities. 



It is always dangerous and not always advisable to use 

 one character to distinguish genera. On this account I 

 have rejected the various genera of Fringillidse, about which 

 there is so much diversity of opinion — I mean Cai-duelis, 

 Spinas, and Acanthis. These are, indeed, grouped by colour 

 alone in the new ' List of British Birds,^ but wrongly, in my 

 opinion. If we go by the shape of the bill we must accept 

 the genera Carduelis (including Spitms), maybe Acanthis, 

 and certainly Cannabina ; if by colour Carduelis, Spinus, 

 Acanthis (including Cannabina !). I cannot agree to either. 

 In view of the curious " Chrysomitris ambigua " Oustalet 

 (Bull. Mus. Hist. Nat. Paris, 1896, p. 186), which has the 

 bill of a Siskin and the wings coloured exactly like a 

 Greenfinch, and which appears to merge into Chloi'is sinica, 

 one might even unite Chloris and Spitms, or, as I call it, 

 Carduelis ! 



I shall always agree to separate genera on account of a 

 longer and shorter beak, if there are o^y additional peculiar- 

 ities, and if the gulf is unbridged ; but I shall unite them 

 without hesitation, if they are connected by intermediate 

 forms. 



* This case has been discussed in 'Novitates Zoologicae/ 1806, 

 pp. 70-73. 



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