102 
NATURAL HISTORY 
LETTER XXXIL 
TO THOMAS PENNANT, ESQUIRE. 
Selborne, Oct. 29, 1770. 
FTER an ineffectual searcli in Linnaeus, Bris- 
son, &c., I begin to suspect that I discern my 
brother's Hirundo hyberna in Scopoli's new 
discovered Hirundo rupestris, p. 167. His 
description of Supra murina, subtus albida; 
rectrices macula ovali alba in latere interno; pedes nudi, 
nigri; rostrum nigrum; remiges obscuriores quam plumce 
dorsales ; rectrices remigibus concolores ; cauda emarginata 
necforcipata;'^ agrees very well with the bird in question; 
but when he comes to advance that it is statura Hirun- 
dinis urbicoe/' and that ^' definitio Hirundinis riparice Linncei 
huic quoque convenit/^ he in some measure invalidates all he 
has said ; at least he shows at once that he compares them 
to these species merely from memory : for I have compared 
the birds themselves, and find they differ widely in every 
circumstance of shape, size and colour. However, as you 
will have a specimen, I shall be glad to hear what your 
judgment is in the matter.^ 
Whether my brother is forestalled in his nondescript or 
not, he will have the credit of first discovering that they spend 
their winters under the warm and sheltery shores of Gib- 
raltar and Barbary.^ 
* It seems highly probable that Gilbert White's suspicion of the 
identity of his brother's Gibraltar swallow with the Hirundo rupestris 
was correct ; indeed, if the Gibraltar bird exhibited a white spot on the 
inner web of each of the tail feathers (except the two intermediate 
ones), it could have been no other than the bird first characterized by 
Scopoli, in his " Annus Primus," under the name quoted. According to 
M. Temminck the rock swallow is abundant along the shores of the 
Mediterranean. — Ed. 
^ " This remark," says Mr. Bennett, " is not to be understood as 
miting the residence of the rock swallow at Gibraltar to the winter 
