58 BANGS — ROUGH-WINGED SWALLOWS [Vern 
After studying a large amount of material I have become con- 
vinced that intergradation occurs between most, if not all, of the 
forms of Stel/gidopteryx, and that the relationships of the various 
representative geographical races are best expressed in trinomials. 
Even the light-colored rump of the two central forms appears to 
be only a subspecific character. Ina series from Divala, Chiriqul, 
some specimens have the rump as light as Panama birds, while 
in others it is only just perceptibly lighter than the back. The 
different races, each occupying a considerable area, are merely 
steps from the daintily colored South American forms to the 
plainly clad S. serripennis of North America. : 
The forms of the American rough-winged swallow that seem 
to me worthy of recognition may be arranged by the colors of the 
fully adult plumage (none of the forms differ much in size or 
proportions), as follows. 
Stelgidopteryx ruficollis ruficollis (Vieill.). 
Hirundo ruficollis Vieill., Nouv. Dict. d’Hist. Nat., Vol. XIV, 1817, p. 523. 
Type locality.— Brazil. 
Geographic distribution. La Plata region, Bolivia and Brazil (exact limits 
of range unknown). 
Characters.— Upper parts sepia, the top of head darker, the rump not paler 
than back; primaries and rectrices clove-brown; tertials, usually, except in 
very worn plumage, edged with drab; throat orange buff; breast and sides 
pale grayish sepia—a little paler than back; belly and under tail coverts 
naples yellow, the longer under tail coverts with large subterminal clove-brown 
marks across the feathers. 
Stelgidopteryx ruficollis aqualis* subsp. nov. 
Type, from Santa Marta, Colombia, ¢ adult, no. 5458, coll. of E. A. and 
O. Bangs, collected Jan. 20, 1898, by W. W. Brown, Jr. 
Geographic distribution.— Eastern South America from Guiana to Santa 
Marta region of Colombia, and south in the Andes through western Colombia 
to Ecuador. Probably intergrading all along the southern part of its range 
with S. rjficollis ruficollis. 
1 4iqualis — looking alike, resembling. 
