1869.] ON THE GENUS MICRASTUR. 365 
(in the place of Brachypterus of Lesson, previously employed), 
embraces a series of American Hawks with the general structure of 
Accipiter, but distinguished by their short toes and more rounded tail. 
We have examined specimens of seven species of it, which may be 
shortly distinguished as follows :— 
A. Majores: subtus albi fere unicolores. 
@. WAjOY, SUPTA NIPTICANG.........0.ceeceersercesrecseeerones 1. M. semitorquatus. 
G-MiNOL, SUPA CINETOUS”’s..2.-25...sJanccesaveceecssneces es 2. M. mirandollit. 
B. minores: subtus albi, dense transfasciati. 
a. dorso rufo: pileo cinereo: 
w’, voinor : dorso dilutiore rufo..............se0eees 3. M. rujicollis. 
6”, major: dorso saturatiore rufO ......eeee eee 4, M. zonothorax. 
6. dorso cinereo: pileo concolore: 
a’. yentre imo et crisso albis immaculatis......... 5. M. gilvicollis. 
b”. yentre imo et crisso cinereo transfasciatis : 
a”, dorso ilutiore CiINCTEO ........-seeeeeeeeees 6. M. leucauchen. 
b/”. dorso saturatiore cimereO ............1000 7. M. guerilla. 
1. MicRASTUR SEMITORQUATUS. 
Sparvius semitorquatus, Vieill. N. D. x. p. 322, et Ene. Meéth. 
. 1263. 
, Sparvius melanoleucus, Vieill. N. D. x. p. 327, et Enc. Méth. 
p- 1267. 
Falco brachypterus, Temm. Pl. Col. 116 (jr.) et 141 (adult.). 
Micrastur brachypterus, Pelz.Orn. Novara, p. 12, et Orn. Bras. p. 7. 
Micrastur semitorquatus, Scl. et Salv. Ibis, 1859, p. 218; Law- 
rence, Ann. L. N. Y. ix. p. 134. 
Climacocercus brachypterus, Burm. Syst. Ueb. ii. p. 88. 
‘alco leucomelas, Licht. Doubl. p. 62. 
Carnifex naso, Lesson, Rev. Zool. 1842, p. 379. 
Falco percontator, Cabot, Boston Journ. iv. p. 462. 
Hab. Rio Janeiro (Natt.); Mato Grosso (Natt.) ; Borba (Natt.); 
Rio Negro et Rio Brancho (Naét.) ; Costa Rica (Zeledon) ; Guate- 
mala (Salvin) ; Yucatan (Cabot). 
This species, well known by the figures of the adult and young m 
Temminck’s ‘ Planches Coloriées,’ is widely distributed throughout 
Tropical America, from Yucatan to Paraguay. It does not, however, 
appear to occur in the wood-region of Eastern Brazil, nor have we 
yet seen specimens from New Granada and Ecuador. In Guatemala 
it seems to be rare, as Salvin only obtained one specimen from 
Retaluleu, in the forest-region bordering the Pacific. Another 
Guatemalan specimen, in the Norwich Museum, is probably from 
Vera Paz. 
The large size of this bird renders it easily distinguishable from 
every other species of the genus. 
2. MiIcRASTUR MIRANDOLLII. 
Astur mirandollii, Schl. Ned. Tijdschr. i. p. 130, et Mus. de P.- 
B. Astures, p. 27. 
Micrastur macrorhynchus, Natt. MS.; Pelz. Orn. Novara, p. 21, 
et Orn. Bras. p. 7. 
