

Supposed occurrence of Hirundo bicolor in England. 131 



"British-bird" students who find in these alien immigrants a great 

 cause of perplexity. To whatever country we go, we are, perhaps 

 before we have well ascertained the number of the bond fide species, 

 puzzled by some wanderer turning up exactly where he was least 

 wanted. In my own opinion, the ornithologist must accept his 

 position with all its responsibilities ; he chooses to study a class of 

 beings, some of whom, for all sublunary purposes at least, are blest 

 with almost infinite powers of locomotion. He must therefore not 

 complain if in the course of a morning's walk here in England, an 

 Australian Swift flies in his face, or he picks up a dead Crossbill of a 

 Transatlantic species ; and he must invoke no Deus ex machina in the 

 shape of an auxiliary- screw clipper or a careless aviary-keeper to 

 account for the incident. Facts like these hardly admit of a doubt, 

 and force themselves day by day more and more upon the notice of 

 the thoughtful naturalist. For some time, indeed, European orni- 

 thologists have been accustomed to regard the properly authenticated 

 appearance of an exotic species, which there may be good reason to 

 suppose to have reached our shores without intentional human aid, 

 as sufficient ground for including it in the list of our birds. But as 

 observers have of late so largely increased, so have these occurrences 

 been more frequently noticed ; and it seems absolutely necessary to 

 prescribe some limit to prevent our really native species from being 

 outnumbered by these foreigners. The difficulty is to know where 

 to draw the line ; and to this point I would invite the careful con- 

 sideration of naturalists. It may be all very well to call Thalassi- 

 droma Wilsoni and Mergus cucullatus European birds ; but because 

 a single individual of Regulus calendulus or Dendrceca virens has 

 reached the Old World, it is absurd to include either of those species 

 in its Fauna. I cite these instances because they are all from that 

 continent whence most of our occasional visitants arrive — so much 

 so, that one is almost driven to the conclusion that there is no prima 

 facie reason why examples of the greater number of birds of Eastern 

 North America should not, favente zephyro (the prevailing strong 

 wind in Western Europe), make their appearance on our shores in 

 course of time. Then, on the other hand, the last two additions to 

 the list of so-called " British birds " have been from the opposite 

 quarter. Are Syrrhaptes paradoxus and Xema ichthyaetus to take 

 their places in the books elucidating British Ornithology by the side 

 of the Red Grouse and the Peewit Gull ? It appears to me that we 

 gain nothing by deferring a decision on the subject, and I trust that 

 these remarks will not be deemed unnecessary by those who are 

 competent to deal with the matter. 

 Elveden, 28 February, 1860. 



Description of a New Genus of Boidje discovered by 

 Mr. Bates on the Upper Amazon. By Dr. J. E. Gray. 

 Fam. BoidjE. 

 Chrysenis, n. g. 



Head rather large, rather depressed, covered with scales, the front 

 half covered with small symmetrical shields, as follows : — two pair 



9* 



