60 
BULLETIN OF THE NUTTALL 
Troglodytidae. 
2. Thryomanes brevicauda. 
3. Salpinctes guadalupensis. 
Thryomanes bewicki. 
Salpinctes obsoletns. 
Fringillidae. 
4. Carpodacns ampins. 
5. Junco insnlaris. 
6. Pipilo consobrinus. 
Carpodacns frontalis. 
Junco annectens. 
Pipilo maculatus. 
Picidae. 
7. Colaptes rufipileus. 
Colaptes mexicanus! 
Falconidae. 
8. Polyborus lutosus. 
Polyborus tharus.^ 
The more prominent characteristics of these Guadalupe birds, as 
compared with the mainland forms, are (1) increased size of the 
bill and feet, (2) shorter wings and tail, and (3) darker colors ; 
these variations are by no means uniform, however, in the several 
species, the, differentiation being in some slight, while in others it 
amounts to almost generic distinctness ; but, what is very remark- 
able, and of great interest in connection with the subject in hand 
is, that no matter how great may be the modification of form and 
proportions, the specific characters^ so far as coloration is concerned^ 
are in every case strictly preserved ! t Thus, Carpodacns ampins has 
the wdng and tail barely longer than C. frontalis, but the bill is 
three times as large, and the feet twice as stout, ivhile the colors and 
markings are substantially identical; Junco insidaris has precisely 
the same plumage as J. annectens (except that the shades of color 
are just perceptibly darker), but the bill is so elongated, and the 
wings and tail so much abbreviated, that in form it is much more 
like the species of Ammodromus than those of typical Junco ! Thry- 
omanes brevicauda does not differ more than just appreciably in 
colors and marking from T. bewicki, but the difference in form is so 
great as to render it necessary either to institute a new genus, or, 
as the only alternative, to draw up a generic diagnosis entirely 
^ Singularly enough, the Polyhorus from Guadalupe resembles much more 
closely the South American species than that _ from Mexico (P. cheriway), 
though it is very distinct from- either. 
The only water-bird collected on the island was a specimen of Colymhus pa- 
eificus, in perfect breeding plumage, found dead on the shore. 
+ With the sole exception of Polyhorus lutosus. 
