Recently published Ornithological Works. 197 
intermediate links to connect it with T. felix. Moreover the 
bird has a distinct island habitat^ which renders it very un¬ 
likely that intermediate forms exist. That it is clearly de¬ 
rivative from the mainland species does not preclude its 
being a distinct species, which we suspect it really is. 
Mr. W. H. Henshaw returns to the discussion respecting 
Selasphorus alleni, and endeavours to show that he was right 
in bestowing a name upon the green-backed Selasphorus, 
using S. rufus (Gm.) for the w^ell-known rufous-backed 
form. Mr. Elliot, holding the opposite view, has renamed 
the rufous-backed bird S. henshawi. The whole point turns 
upon Latham^s description in the ^ General Synopsis ’ (i. 
p. 785), as from it Gmelin framed his diagnosis. One of 
Latham^s characters, between the wings a greenish gloss,^'' 
supports to some extent the view that he had the green- 
backed bird before him. This, however, is quite set aside 
a little further on when the green back of the female is 
compared with the rufous back of the male. Swainson^s 
testimony (F, B.-Am. ii. p. 496) is entirely in favour of 
Latham^s bird being the rufous-backed form. He describes 
a specimen in his own possession, which he bought from 
Bullock, who had it from Sir Joseph Banks, who probably 
received it from some one who accompanied Cook in his last 
voyage*. This specimen was doubtless a typical one. The 
peculiarity of the range of the two forms appears capable of 
being accounted for by viewing the northern rufous-backed 
bird to be a migratory species spending its summers in Western 
America north of California, and its winters in the Mexican 
highlands. On the other hand the Californian S. alleni is 
probably nearly sedentary, or, at all events, performs no 
such lengthened migration as its near ally. On the whole 
we think Mr. Henshaw right in his view of the question. 
Mr. William Brewster has an article on the first plumage 
of a number of American birds; and he is followed by Mr. J. 
A. Allen, who criticises Mr. Wallace's ^Theory of Birds’ 
Nests,’ to show its inadequacy as applied to the birds of the 
* [I have searched for this specimen in the Swainson Collection at 
Cambridge, hut have not succeeded in finding it.—0. S.] 
