226 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 150 



Paraguay. Kirke Swann recognized the two forms and in 1921 

 named the southern one australis, a name, however, that is antedated 

 by rufulus Vieillot of 1816. 



Plotnick (Hornero, 1956, pp. 136-139), in a study of the osteology, 

 has established that Heterospisius is a genus of the subfamily 

 Buteoninae and not of the Accipitrinae, where it has been placed by 

 Peters and others. This I find fully verified on examination of 

 skeleton material available. 



PARABUTEO UNICINCTUS HARRISI (Audubon): Harris's Hawk; 

 Gavilan Andapi6 



Buteo Harrisi Audubon, Birds Amer. (folio), vol. 4, 1837, pi. 392. (Between 

 Bayou Sara and Natchez, Mississippi.) 



A black hawk with white rump and tail tip that differs from others 

 with this color pattern in the rufous markings on the back and 

 wings. 



Characters. — Length 480 to 560 mm. Adult, above fuscous-black ; 

 forehead and superciliary streaked with white ; nape feathers white 

 basally; wings dull black, with outer webs of primaries and ends of 

 secondaries edged with grayish white ; lesser and middle wing coverts 

 rufous; greater coverts, back, and rump feathers edged or tipped 

 with rufous ; tail black, with base, including upper tail coverts and 

 tip, white; below dull black; feathers of throat and sides of head 

 edged with white to produce streaks ; legs and flanks rufous, mottled 

 indistinctly with white ; under tail coverts buffy white ; under wing 

 coverts cinnamon, mottled with white, more heavily toward outer 

 edge of wing; a prominent patch of white near center of underside 

 of primaries, extending to their bases, with indistinct light barring 

 toward tips. 



Immature, fuscous above, with indistinct barring, edging, and 

 streaking of cinnamon-buff, especially on wings; lesser and middle 

 coverts rufous more or less variegated with black; superciliary 

 cinnamon-buff; throat white, lined with fuscous; undersurface white 

 to cinnamon-buff, streaked and spotted heavily with dull black ; legs 

 and flanks buffy white, barred narrowly with dull rufous ; under sur- 

 face of tail grayish white, barred narrowly with blackish brown ; 

 rump, upper tail coverts, and upper surface of tail as in adult, but 

 with a narrow margin of cinnamon-buff above the white tail tip. 



Measurements (from Friedmann, U. S. Nat. Mus. Bull. 50, pt. 

 10, 1950, p. 371).— Males, wing 318-331 (323) ; tail 215-262 (234), 

 culmen from cere 24-28 (26.3), tarsus 84-90 (86.2) mm. 



