72 



Annals of the Carnegie Museum. 



Microrhopias intermedia 

 Sakcsphorus pulcJiellus 

 Myiarchus tyrannulus tyrannulus 

 Ekcnia gaimardii bogotensis 

 Phccomyias tenuirostris 

 Euscarthmus impiger 

 Mini us gilvus columbianus 



Polioptila plumbiccps 

 Helcodytes minor albicilius 

 Pachysylvia aurantiifrons auran- 

 tiifrons 

 Ccereba luteola lutcola 

 Cacicns eel a 

 Thraupis glaucocolpa 



Some of the above we know do not range westward beyond the 

 semi-arid region of the northeast coast, as for instance Microrhopias 

 intermedia, which is replaced in the lower Magdalena Valley by a 

 distinct species, Microrhopias alticincta liondcr; Cacicns cela, which 

 is similarly replaced by Cacicns vitellinus; and Elccnia gaimardii bogo- 

 tensis, replaced by Elccnia gaimardii macilvainii. (See Figure 2.) 



Fig. 2. Range of Microrhopias intermedia (i), a species of the Arid Trop- 

 ical Zone which enters the Santa Marta Region from the east, but is replaced 

 in the Magdalena Valley by an allied form, M. alticincta liondcr (2). 



The presumption is strong, therefore, that the species in this list have 

 reached their present range in the littoral of Colombia by extending 

 their range westward along the coast, some having gone farther 

 than others. At any rate, few of these forms are yet known from the 



