BIRDS FROM COSTA RICA—-WETMORE 30 
Van Rossem gives the wing of 10 specimens of his excubitor from 
northwestern México as 280 to 302 mm., and the tail as 235 to 250 mm., 
and of 10 chapman: from eastern México and Central America as, wing 
255 to 275 mm. and tail 200 to 230 mm. In material that I have 
examined these figures do not hold. For example, there is one bird 
from Palmul, Quintana Roo, with the wing 281 and the tail 200,one from 
Tres Zapotes, Veracruz, with these measurements 292 and 214 mm., 
and one from Paso Nuevo, Veracruz, 289 and 232 mm., as well as one 
from Progreso, eastern Guatamela, with the wing 307 and the tail 
230 mm. These are mingled in the same regions with specimens of 
more ordinary dimension. Difference in size definitely cannot be 
correlated with geographic range, as the wing in birds from Veracruz 
and Tabasco in eastern México varies from 255 to 292 mm., and from 
Yucatan and Quintana Roo from 268 to 281. There does not seem 
to be any particular difference therefore for birds of western México. 
Color differences also are variable. It appears that only one race can 
be recognized in México. 
Herpetotheres cachinnans cachinnans (Linnaeus): 
Falco cachinnans LINNAEUS, Systema naturae, ed. 10, vol. 1, 1758, p. 90 (Surinam). 
Darker, blacker above; immature with light margins on dorsal 
feathers darker, more chestnut-brown. 
Range: From Honduras (possibly from El Salvador) south through 
Central America to Peri and the Amazon Valley in Brazil. 
Various specimens from Honduras south to Panamé appear some- 
what intermediate toward the more northern form, but on the whole 
birds from this area average very closely similar to a good series from 
Surinam. 
The buffy cast of the light areas of head and breast common in 
this hawk is intensified in birds from the western parts of Ecuador and 
Colombia, but this is too inconstant to warrant recognition of a 
separate race fulvescens,? which some have suggested recently might 
‘be extended well north into Central America. This fact has been 
previously indicated by Peters.* ; 
I have examined two specimens of the supposed race maestus,® 
proposed on the basis of paler color, but this difference appears due 
to the skins being cleaner than the average as they come from a drier 
area, so that they also must be placed with cachinnans. 
The wing in six birds from Surinam, the type locality, varies from 
258 to 279 mm. A series from the entire range in South America runs 
from 247 to 286 mm., and one from Central America from 256 to 294. 
3 Herpetotheres cachinnans fulvescens Chapman, Bull, Amer. Mus. Nat. Hist., vol. 34, 1915, p. 638 (Alto 
Bonito, 1,500 feet, west slope of western Andes, Antioquia, Colombia). 
4 Check-list of birds of the world, vol. 1, 1931, p. 276. 
5 Herpetotheres cachinnans maestus Bangs and Noble, Auk, 1918, p. 444 (Bellavista, Perf). 
