222 Proceedings of the Biological Society of Washington. 



"Allied to R. sulphur escens, but differs in being olive grey above instead 

 of green; the head somewhat darker and inclining to lead-colour; tail- 

 feathers pale brown, edged with whitish; quills also pale brown, margined 

 with olive-grey. The two bars on the wings, formed by the margins of 

 the median and greater coverts, are white instead of yellow; the throat and 

 chest olive-grey, not yellow; the middle of the abdomen whitish, in place 

 of yellow; the under tail-coverts buff towards the ends; the under wing- 

 coverts white instead of yellow. Bill black above, greyish white below; 

 tarsi and feet bluish slate coloured; iris brown. Total length 5.2 inches; 

 culmen 0.6; wing 2.55; tarsus 0.8." (Chubb I. c. orig. descr.) In the same 

 paper Chubb records R. sulphurescens sulphurescens from the same lo- 

 cality. 



Rhynchocyclus flaviventris flaviventris (Wied). 



Muscipeta flaviventris Wied. Beitr. Naturg. Bras. (3), ii, 1831, p. 929 

 (Rivers Mucuri and Alcobaca, southern Bahia, Brazil). 



Rhynchocyclus flaviventris aurulentus Todd, Proc. Biol. Soc. Wash., XXVI, 

 1913, p. 171 (Momotoco, Santa Marta, Colombia). 



Range: Northern and eastern Colombia (Santa Marta; Lower Magdalena 

 region; Cucuta; "Bogota" region); Venezuela (Puerto Cabello; Tocuyo; 

 Cumana; Rio Aurare; Caicara and along the middle Orinoco River, etc.); 

 Trinidad; Tobago; British Guiana; northern and eastern Brazil (Amazonian 

 region from about the Rio Branco, eastward to Rio Tocantins; Rio Ja- 

 munda; Para; Jua and Quixada, Ceara, and southward to Rio Araguaya, 

 Goyaz and Rio Mucuri, Bahia). 



In this group R. f. viridiceps and R. f. borboe appear to be well marked 

 races, but I am unable to separate the Santa Marta bird (aurulentus Todd) 

 from the typical form. There is apparently considerable individual vari- 

 tion (either seasonal or due to difference in age) in the coloration of the 

 under parts and borders of wing coverts, and to a somewhat lesser degree 

 the same may be said of the coloration of the upper parts. The brightest 

 examples are from Ceara, although I can not distinguish them from some 

 specimens from Santa Marta, and from both of these localities a few se- 

 lected specimens are unquestionably brighter than any examples I have 

 seen from Bahia. Most of the Bahia specimens are old skins and the single 

 fresh skin is as brightly colored as most of the Santa Marta specimens. 

 From the material before me the differences are slight and apparently not 

 constant. Two specimens from the Rio Branco show a slight tendency 

 towards R. f. borbce, but are much nearer R. f. flaviventris. 



I have examined 61 specimens of this form from the following localities: 

 Colombia (Santa Marta region, Momotoco, Bonda, etc., 18; Lower Magda- 

 lena River and Cucuta 5); Venezuela (Rio Aurare 2; Cumana 1; Suapure, 

 Maripa and La Union 9) ; Trinidad 6; Tobago 3; Brazil (Bahia 7; Rio Branco 

 region 5; Quixada and Jua, Ceara 5). 



Rhynchocyclus flaviventris viridiceps (Sclater & Salvin). 



Rhynchocyclus viridiceps Sclater & Salvin, P. Z. S. Lond., 1873, p. 280 

 (Pebas, N. E. Peru). 



