1917.] Chapman, Distribution of Bird-life in Colombia. 631 



(4474) Molothrus bonariensis atronitens Cab. 



Molothrus atronitens Cab., Schomb. Reisen in Brit.-Guian., Ill, 1848, p. 682 

 (British Guiana). 



I refer to this species an immature male from La Morelia. It measures : 

 wing, 101; tail, 75; tarsus, 25.7; culmen, 18 mm. 



Specimens from Merida, Puerto Cabello and Maripa, Venezuela, com- 

 monly referred to Molothrus venezuelensis Stone appear to me to be obvious 

 intergrades between Molothrus bonariensis cabanisi (Cass.) and M. b. atro- 

 nitens. Males can be exactly matched in color by both Colombian and 

 Trinidad specimens, but the females are intermediate in color being some- 

 what darker than cassini and not so dark as atronitens. In size these birds 

 are nearer cabanisi to which, on the whole, I should refer them. 



La Morelia, 1. 



(4475) JMolothrus bonariensis cabanisi Cass. 



Molothrus (Lampropsar) cabanisii Cass., Proc. Acad. N. S. Phila., 1866, p. 22 

 (Type from Santa Marta in Am. Mus. Nat. Hist, labelled by Cassin " Lampropsar 

 cabanisii Cass.")- 



Molothrus discolor Sol. & Salv., P. Z. S., 1879, p. 509 (Concordia; Medellin; 

 Sta. Elena). 



Molothrus cassini Allen, BtTLL. A. M. N. H., XIII, 1900, p. 163 (Arihueca; Caoa- 

 gualito). 



Our specimens are all from the Tropical Zone west of the Eastern Andes. 

 This form is distinguished by its large size and comparatively pale-colored 

 female. 



Caldas, 4; San Antonio, 5; Cah, 5; Miraflores, 5; San Agustin, 2. 



(4475a) Molothrus bonariensis aequatorialis Chapm. 



Molothrus bonariensis cequatorialis Chapm., Bull. A. M. N. H., XXXIV, 1915, p. 

 661 (Barbacoas, Col.). 



Char, subsp.- — Size smaller than that of M. b. bonariensis, the male resembling 

 in color the males of other forms of this species; the female decidedly darker than the 

 female of M. b. cassini and still darker than the female of M. b. ocddentalis, much 

 nearer the females of M. b. atronitens and M. b. bonariensis, but much larger than the 

 former, somewhat larger than the latter and with a larger, heavier bill. 



Inhabits the Tropical Zone of southwestern Colombia southward into 

 Ecuador. Its relationships appear to be with true bonariensis rather than 

 with the geographically nearer cabanisi. On the coast of Peru it is replaced 

 by the paler M. b. ocddentalis. 



Tumaco, 1 ad. cf , 2 juv.; Barbacoas, 1 ad. 9,1 juv. 



