58 
BULLETIN OF THE NUTTALL 
measurements taken by Mr. Allen. As he informs me, however, 
that the variation in this respect is very small, it is probable the 
average "would be little changed by their addition. 
In bestowing the specific name, I have paid but a deserved com- 
pliment to the zeal and enthusiasm of Mr. C. A. Allen, but for 
w^hose efforts in obtaining the specimens necessary for comparison, 
and careful field-notes, the species might have remained for a long 
time still unrecognized. 
THE BIRDS OF GUADALUPE ISLAND, DISCUSSED WITH 
REFERENCE TO THE PRESENT GENESIS OF SPECIES. 
BY ROBERT RIDGWAY. 
The importance of insular faunae in their bearing on '^the sub- 
ject of the derivation of species, has been recognized by eminent 
writers; and certain islands, remote from the mainland, among 
which may be mentioned the Galapagos, have received marked 
attention. An excellent memoir upon the birds of the latter group 
has lately been published by Mr. Osbert Salvin,* who discusses the 
relationship of certain peculiar forms to their continental allies, 
and even goes so far as to point out among the latter the present 
representatives of the parent stocks from which the genera now 
peculiar to the Galapagos have been derived. That Mr. Salvin is 
probably correct in his conclusions, is very strongly indicated by 
certain facts developed from a study of the fauna of Guadalupe, 
where in the case of almost every species, precisely the same local 
modifications are observable ; the process of change in the latter 
case, however, has been either more recent or more gradual, since 
close affinity to continental representatives is clearly seen in every 
species, the extreme differentiation met with in the Galapagos types 
not having yet been reached. t 
* On tke Avifauna of the Galapagos Archipelago. By Osbert Salvin, M. A., 
F. R. S., etc. Transactions of the Zoological Society of London, Vol. IX, 
Part IX, pp. 447-510, pis. Ixxxiv - Ixxxix. May, 1876. 
t These modifications seem to be, (1) enlargement, or elongation, of the bill 
and feet, (2) abbreviation of the wings and tail, and (3) darkening of the colors 
