484 
U. S P. R. K. EXP. AND SURVEYS ZOOLOGY — GENERAL REPORT. 
PEUCAEA, Audubon. 
Peucaea, Audubon, Synopsis, 1839. Type Fringilla aestivalis. 
Ch. — Bill moderate. Upper outline and commissure decidedly curved ; gonys nearly straight. Legs and feet small ; the tarsus 
about equal to the middle toe; the lateral toes equal, their claws falling considerably short of the middle one ; the hind toe 
reaching about to the middle of the latter. The outstretched feet reach only to the middle of the tail. The wing is very short, 
reaching only to the base of the tail ; the longest tertials do not exceed the secondaries, while both are not much short of the 
primaries ; the outer three or four quills are graduated. The tail is considerably longer than the wings ; it is much graduated 
laterally ; the feathers, though long, are peculiarly narrow, linear, and elliptically rounded at the ends. 
Color beneath plain whitish or brownish, with a more or less distinct dusky line each side of the chin. Above with broad obso- 
lete brown streaks or blotches. Crown uniform, or the feathers edged with lighter. Inner tail feathers with obsolete transverse 
dusky bars. 
This is a very well defined group, with a curved upper mandible ; short toes ; very short and 
much rounded wings, less than the tail ; a long, much graduated tail, with the feathers narrow, 
linear, and elliptical at the end. This character of the tail, with that of the unspotted under 
parts and black streak on each side of the chin, and the yellow edge to the wings in two of the 
species, are all strong distinctive features. 
Synopsis of species. 
A. Maxillary black streak narrow; edge of wing yellow (inconspicuously.) Head above streaked. 
Feathers above with the central portion dark chestnut ; those of the back with broad 
streaks of brown. Throat, breast, and sides tinged with yellowish ash.... P. aestivalis. 
Feathers above paler ; those of back with narrow central streaks of brown, or else 
wanting. Beneath paler ; throat nearly white P. cassinii. 
B. Maxillary stripe very distinct. Head above nearly uniform reddish. Edge of wing 
grayish white P. rujiceps. 
Comparative measurements of species. 
Catal No. 
Species. 
Locality. 
m 
Length. 
Stretch of 
wings. 
2.30 
2.64 
2. 50 
2 24 
Tail. 
Tarsus. 
Middle toe. 
Its claw 
alone. 
Hind toe 
and claw. 
Hind claw 
alone. 
Bill above. 
Along gape. 
Specimen 
measured. 
3831 
63-27 
3070 
do. 
10244 
do. 
5.48 
5.82 
6.10 
5.10 
5.70 
6.00 
6.50 
2.80 
3.05 
3.12 
2 50 
0.77 
0.73 
0.84 
0.72 
0.72 
0.69 
0.79 
0.70 
0.17 
0.17 
0.18 
0.16 
0.50 
0.64 
0.55 
0.23 
0.26 
0.24 
0.42 
0.46 
0.49 
0.45 
0.47 
0.50 
0.48 
0.50 
Peucaea cassinii 
Texas 
Los Nogales, Mex 
s 
"q" 
do 
7.50 
8.00 
3 
2.36 
2.50 
2.78 
0.76 
0.74 
0.14 
0.24 
0.44 
0.52 
PEUCAEA AESTIVALIS, Cabanis. 
Bachman's Finch. 
Fringilla aestivalis, Licht. Verz. Doubl. 1823, 25, No. 254.— Bonap. Conspectus, 1850, 481. 
Peucaea aestivalis, Cabanis, Mus, Hein. 1850, 132. 
■ Fringilla backmani, Aud. Orn. Biog. II, 1834, 3GG ; pi. 165. 
Ammodromus bachmani, Bon. List, 1838. 
Peucaea bachmani, Aud. Syn. 1839.— Ib. Birds Am. Ill, 1841, 113 ; pi. 176.— Bon. Consp. 1850, 481. (Type.) 
Fringilla aestiva, Nutt. I, 2d ed. 1840, 568. 
" Summer finch, Latham, Synopsis, 2d ed. VI, 136." Nuttall. 
