1917.] 



Chapman, Distribution of Bird-life in Colombia. 



113 



Doubtless the absence of some of these species from western Colombia 

 may be apparent rather than real, but such common, conspicuous species 

 as Manacus manacus, and Arremenops conirostris are not likely to escape 

 the collector, if present. Possibly the heavy forests of the Colombian- 

 Pacific may have prevented the entrance of Arremenops into this region, 

 but this explanation cannot be offered to account for the absence of Curu- 



Fig. 7. Known range of Arremonops conirostris. Illustrating the apparent absence on the 

 Colombia-Pacific coast, north of the Patia River, of a species represented in Panama and northern 

 Colombia by the same or an allied species. 



1. Arremenops conirostris chrysoma. 2. Arremenops conirostris inexpectata. 

 3. Arremenops conirostris richmondi. 4. Arremenops conirostris conirostris. 



cujus melanurus, while the theory of transandean origin will explain why the 

 west Ecuador form of this species should agree with that of Amazonia (C 

 melanurus melanurus) rather than with that of the Cauca-Magdalena 

 district (C. m. macrouru^s). 



