72 FALCONID. 
subtus nigris; remigibus intus albis, griseo marmoratis vel fasciatis. Long. tota circa 15-8, ale 11-7, 
caude 6-2, tarsi 2:25. (Descr. exempl. ex Alvarado, Mexico. Mus. nostr.) 
Juv. Fuliginoso-niger ; cauda fasciis nigris 8 notata: subtus fasciis celatis albis vel ochraceis variegatus 3 
facie laterali nigricante, regione parotica nigro lineata. (Descr. maris juv. ex Miami, Florida. Mus. 
nostr. ) 
Hab. Nortu America, Florida > ® ”.—MExiIco (Boucard *"), Tamaulipas (Mus. Norv." 38), 
Alvarado (Ferrari-Perez), Jalapa (de Oca”! 24}, Tehuantepec city 26° 'Tonala 4 
(Sumichrast), Cozumel Island (U.S. S. ‘Albatross’ **°); Guatemaza!! 20 (Skinner °), 
Coban (0. 8.2); Nicaragua, Escondido River (Richmond ®); Costa Rica, San José 
(Cherrie*), Irazu (Underwood), San Antonio (v. Frantzius), La Palma (Zeledon, 
v. Frantzius); Panama, Calobre, Calovevora 2 (Arcé).—CoLoMBIA"* ; VENEZUELA? ; 
Amazons 12; Brazit?>; Peru’; Botivia. 
The black form of this Buzzard (B. fuliginosus) was originally described by 
Dr. Sclater!7 from a specimen from Tamaulipas in the Norwich Museum. In the 
‘Catalogue of Birds’ (vol. i. p. 185) the species was referred to B. obsoletus (i. e., 
B. swainsoni of this work), but this was a mistake. Since the latter work was published 
B. fuliginosus has been considered by some ornithologists to be merely a melanistic 
phase of B. brachyurus, whilst others treat the two forms as distinct. The latter 
view has recently been taken by Professor Ridgway (‘ Manual of North American 
Birds,’ 2nd edit. pp. 236, 237). Both forms occur in Florida, and throughout Central 
America to Colombia, but in other portions of South America only the white-breasted 
bird has been found, and the black-breasted one is either very rare or has escaped 
observation. | 
The question as to whether Buteo brachyurus and B. fuliginosus are different 
species, or whether they are phases of a single dimorphic form, must, in face of 
the evidence produced by Mr. W. E. D. Scott, who has found the two supposed 
species breeding together in Florida *’, now be considered as settled. In one instance 
a pair of birds was shot by him, and the female proved to be the white-breasted form 
(B. brachyurus), while the male was the black B. fuliginosus. Subsequent. observations 
“1 the same State have tended to confirm this sexual distinction of colour in the male 
and female; but we are inclined to believe that these differences in the colour of the 
plumage may occasionally be reversed in the two sexes. The bird which has hitherto 
been called B. fuliginosus must, in future, be considered as the melanistic form of 
B. brachyurus. Tn the specimens examined by us we have not found the slightest sign 
of any intergradation, although, in the winter habitat of the species in South America, 
the two forms have not as yet been found in the same locality. 
In a specimen of the dark form (B. fuliginosus) from Mexico, which may not be a 
very old bird, the plumage is not so black as in some others in our collection. One 
from Calobre, in Panama, has a grey shade over the black plumage, and has the under 
tail-coverts broadly banded with white, while the under surface of the quills is almost 
entirely black, with only some ovate white marks towards the base of the primaries 
