394 bulletin: museum of comparative zoology. 



Brabourne and Chubb (Birds of South America, 1912, 1, p. 316) 

 hst both P. atricapUlus (Merrem) and P. viorginatus (Lichtenstein). 

 For the former they give the distribution Ecuador, East Peru, and 

 Guiana; and for the latter East Brazil. From the systematic posi- 

 tion of these names in their list, we judge that these authors considered 

 atricayiUus a form of the inarginaius and not of the polychoyterm 

 group, but, so far as we know, they have not given any reasons for 

 rejecting the names in the sense used by Berlepsch. 



We have examined a fairly large series of P. marginatus from various 

 parts of its range, and find much individual variation. Dark speci- 

 mens with or without mottled backs may be found from the same 

 localities as paler specimens with uniform gray backs. Skins from 

 Bahia, Para, Venezuela, and the Peruvian Amazons, can be readily 

 matched, in color, in a large series from French Guiana. 



We believe that a northern form of P achy r ham phus marginatus is 

 separable only by its smaller size, but the diiference is sufficient to 

 warrant recognition. The two forms are: — 



1. Pachyrhamphus marginatus marginatus (Lichtenstein). 



Todus marginatus Lichtenstein, Verz. doubl., 1823, p. 51 (Bahia). Type. — 



Berlin Museum, adult 9 . 

 Pachyry7icMis albifrom Swainson, Anim. in menag;., 1838, p. 289 ("Brazil" — 



we designate Bahia). Type. — Originally in Swainson collection, o^. 

 Pachyrhynchus sivainsonii Jardine and Selby, lUust. orn., 1829, 2, add. [4], 



no. 6 ("Brasilia"— we designate Bahia). Type.— Originally "in Museo 



Dom. Swainson, et Gulielnii Jardine, Baronetti," — 9. 

 Pachyrhamphus atricapillus (not of Merrem) of authors. 



Subspecific characters. — Adult cf similar to Pachyrhamphus polychopterus 

 tristis (Kaup), and of about the same size, but hind neck gray; forehead with 

 a narrow but distinct whitish band; interscapular region partly black; under 

 parts pale gray. Adult 9 head reddish brown, contrasting with back. 



Measurements. — Male (eight specimens) — wing, 70.0-76.0 

 (73.2); tail, 51.0-56.0 (53.6); tarsus 17.0-18.5 (17.8); exposed cul- 

 men 12.0-13.0 (12.4). 



Female (one specimen) — wing, 70.5; tail, 52.0; tarsus, 19.5; 

 exposed culmen, 12.0. 



Range. — Eastern and southeastern Brazil. 



Specimens examined. — Brazil: Bahia (including trade skins). 



