7O APPENDIX: NO. XLVI. 
Derby, in 1850. I say supposed appearance, because though I have 
not much doubt that the bird was really shot at Derby, there is 
nevertheless quite a possibility of mistake. Some months ago, my 
friend, Mr. John Evans of Darley Abbey, sent for my inspection, 
and afterwards kindly presented to me, the skin of a sort of Swallow 
whose name he had not been able to ascertain, of which he gave me 
the following account :—One day that he called at the shop of 
Mr. Cooke, a bird-stuffer and museum-keeper in Derby, im the 
summer of the year 1850, he was shown the skin of a bird which had 
lately been shot at the Siddals (the name of some common land, I 
believe, in the suburbs of Derby), with eleven Sand-Martins, with 
which this had been considered to make atwelfth ; in skinning them, 
Mr. Cooke had remarked that it was not like the others, and he 
thought it a variety, but asked Mr. John Evans his opinion about it. 
That gentleman did not know what it was, but he bought the skin 
for one shilling, and has had it in his possession from that time 
till he gave it to me some months ago, as I mentioned before. 
Mr. Cooke is since dead. The circumstance of his having skinned 
the birds himself, makes it appear improbable that he should have 
made a mistake, and Mr. John Evans assures me that he does not 
think there were any foreign skins about. I should add, that I 
believe there is no possibility of error since the skin came into 
Mr. John Evans’s possession. The bird now before me is very 
hke the House-Martin, and not much like the Sand-Martins 
in whose company it was said to have been found. When com- 
pared with the former bird, the only difference seen at first is 
the continuous dark colour of the back, instead of being white 
over the tail. On a further examination, the legs are found to be 
quite naked below the knees, instead of downy, as in our Martin. 
These characters are I believe sufficient to refer it to the well-known 
American species called Hirundo (or Chelidon) bicolor, and I find 
my skin to agree with the several specimens of it in the British 
Museum. It is useless to give a particular description unless in 
comparison with a skin of the House-Martin, one of which I do 
not happen to have at hand. It is enough to say that the whole 
of the upper surface has a deep metallic green gloss, approaching to 
purple in some lights, except the tail and the flight-feathers, which 
are dull black; the whole under surface is white except the tail and 
wings, which are of an ordinary neutral tint, whilst on this aspect 
the greater part of the shafts of the primaries is white. ‘The 
occurrence of a specimen of a second species of American Swallow 
in England is no more than anyone, who had satisfied himself of 
the reality of the former event (the occurrence of the Purple 
Martin), would be prepared to expect. No kinds of land-bird once 
driven out to sea seem better qualified for arriving safe at this side 
the Atlantic than the Swallows; but it is a question whether even 
these could accomplish it without the assistance of ships, of which 
land-birds at sea are so often seen by sailors to make use. Also 
they probably require strong and long-continued west winds to 
