NO. 9 BIRDS OF ISLA COIBA, PANAMA—WETMORE IOI 
Remarks.—The resemblance of these birds from Coiba is nearest 
to the populations of T. 0. pusilla found from Costa Rica to México, 
from which, however, the new form is decidedly different. Birds 
from the mainland of Panama average paler than those from farther 
north in Central America, with less black on the crown. It seems 
probable from preliminary study that the latter may warrant recog- 
nition as Tiaris olivacea dissita, a name proposed by Thayer and 
Bangs in 1906. 
The subspecific name of the Coiba form is from the Latin ravidus, 
grayish. 
SPIZA AMERICANA (Gmelin): Dickcissel, Arrocero Americano 
Emberiza americana GMELIN, Systema naturae, vol. 1, p. 2, 1789, p. 872. (New 
York.) 
On January 8 I flushed two from litter scattered over a wet pas- 
ture. Country people often call these birds “veinticuatro,” from their 
habit of ranging in little flocks that popularly are believed always to 
number 24 individuals. 
SPOROPHILA AURITA AURITA (Bonaparte): Variable Seedeater, 
Arrocero Comin 
Spermophila aurita BONAPARTE, Conspectus generum avium, vol. 1, pt. 2, (late 
in) 1850, p. 497. (Panama.) 
A few of these seedeaters were found in the open edge of man- 
grove swamps, particularly near the beaches, which must have been 
their original range as they do not penetrate heavy stands of wood- 
land. They are locally common now at the borders of pastures and 
cultivated areas, which give them a considerable increase in the 
habitat suited to their needs. They were seen especially where there 
were stands of ripened grass heads on which they fed in company 
with the yellow-faced seedeaters. On January 18 I observed them 
mating. 
Recently de Schauinsee*! has treated Sporophila aurita as con- 
specific with Sporophila americana (Gmelin), considering that the 
two are united through a subspecies murallae described by Chapman 
from three specimens from Caqueta in southeastern Colombia. This 
proposal I prefer to leave for further study, since little is known of 
Chapman’s race. The eight males and four females secured on Coiba 
do not differ from specimens from Veraguas east to the Canal Zone. 
81 Proc. Acad. Nat. Sci. Philadelphia, vol. 104, Dec. 23, 1952, pp. 160, 172. 
