Carrion Crow, Nightingale, Serpent, and Toad. 547 



most probably, the Northern Ocean, which separated Britain 

 from the main land : an order of events which is entirely borne 

 out by geological data. The mole, for various reasons con- 

 nected with its economy, would be incapable of crossing from 

 Britain to the shores of Ireland, even were the proximate 

 coasts much nearer than at present : but it does not hence 

 follow, that various other quadrupeds, that are common to 

 the two islands, as stags, foxes, &c, may not have accom- 

 plished the passage, as many of these have been known to 

 perform surprising feats of swimming. The fauna and flora 

 of Ireland present many curious phenomena to the attention 

 of the naturalist ; and it is reported that, ere very long, we 

 are to expect a publication of the former. One of the most 

 interesting features of this is the occurrence, in both islands, 

 of the red ptarmigan (£agopus britannicus) ; a species which, 

 so far as is known, is not found elsewhere, and which is ex- 

 tremely unlikely to have crossed the ocean, and, all circum- 

 stances considered, not very likely to have been introduced. 

 I have never heard, however, that specimens from the two 

 islands have been minutely compared, but should decidedly 

 recommend those who have the opportunity to do so. A 

 correspondent of your Magazine observes (IV. 452.) that the 

 red ptarmigan is found in Ireland, " in floes " [marshes, or 

 morasses, uncut and undrained, covered with heath, bog 

 myrtle (ikfyrica Gale), and different kinds of mosses], " remote 

 from hills or mountains : it is also found in the mountains in 

 abundance." The limited range of this inland species to 

 these islands, and the fact of its occurring alike in both, are 

 circumstances much more worthy of attention than they seem 

 generally to have been considered. 



The carrion crow, it is said, does not occur in Ireland, 

 neither is it known in the north of Scotland. What the ex- 

 tent of its distribution may be along the west of Britain, I 

 cannot say, but suspect that it is every where of rare occur- 

 rence in the mountainous districts. 



The nightingale, I think it will be found, occurs nowhere, 

 save as a rare and accidental straggler, much to the westward 

 of, at most, the third meridian of western longitude, in the 

 British Islands, a line which, it will be observed, just cuts off 

 Devonshire and Cornwall, all Wales and Ireland, together 

 with the greater portion of Scotland : exactly the districts 

 wherein the species does not occur. It appears to migrate 

 nearly according to the lines of longitude, deviating but a 

 very little indeed either to the right or left. Thus, we find 

 that some ascend along the eastern coast of Spain, others by 

 Sardinia and Corsica ; some of which, converging very gra- 



