394 Canon Tristram on the Eighth Volume 



wliile P. persicus is a subspecies of P. c(Bruleus. To au 

 ordinary observer the differences of the former are more 

 marked than those of the latter. Again^ P. haplonotus is 

 made a subspecies of P. xanthogenys, which is sometimes 

 carelessly spoken of as P. jerdonl; while P. beavani, which, 

 from the diagnosis given, as well as in actual fact, is more 

 decidedly differentiated from P. rufonuchalis than is P. hap- 

 lonotus from its conspecific form, is put down as a race, whereas 

 P. castaneiventris is unhesitatingly put down as a species. 

 Sometimes colour is ignored, sometimes size, as constituting 

 specific value; but it is all haphazard. To take the instance 

 of the American P. atricapillus : — under this form P. occi- 

 dentalis is ignored. We are told it is a somewhat differently 

 coloured race, but are not informed what are the differences of 

 colour. P. septentrionalis is also ignored, though we are told 

 the differences, both in size and colour ; while to P. caroli- 

 nensis is granted subspecific rank. Writing with specimens 

 of all these races before us, we are sorry to say we cannot 

 discover the justification for this varied mode of treatment. 

 Certainly the claims of P. septentrionalis seem as great as 

 those of P. carolinensis. But it is needless to multiply 

 instances. The objection is not to the use of the terms 

 " race " and " subspecies,'^ but only to their capricious appli- 

 cation. 



In the formation of a key to the species, valuable as such 

 a key is as an index to the holder of an unnamed specimen, 

 it is also important that, if possible, it should be so arranged 

 that the various species, when classified in accordance with 

 it, shall show some sort of natural order, and that closely 

 allied species shall not be widely separated by the intrusion 

 of a totally different group between them. In this respect 

 the admirable synopsis of Baron de Selys-Longchamps seems 

 to commend itself at once by its simplicity and truthfulness. 

 That accomplished naturalist has happily seized on the salient 

 characters and arranged them in such a manner that every 

 bird, with its subspecies and races, seems to fall into its 

 place in natural order. We venture to reproduce it in 

 translation (Bull. Soc. Zool. France, 1884, p. 76). 



