26 ARKIV FÖR ZOOLOGI. BAND 13. NIO 8. 



portion of the country, from Chiriqui up to the foot of the 

 Dota Mountains. 



I have no doubt that these varying statements depend 

 upon the difficulty in classifying birds exhibiting inter- 

 mediate characters. We must remember, that Nelson (Proc. 

 Biol. Soc. Wash. XVII, 1904, p. 45) based his description of 

 this subspecies only upon two examples, mala and female, 

 and these were from Panama. Of his description we there- 

 fore obtain no knowledge about the possible variation of the 

 new form, neither concerning colour nor dimensions. 



If we compare Nelson's description with that given by 

 RiDGWAY, we shall find the latter leaving room for more 

 aberrant individuals. Nelson characterizes the crown as 

 intensely black in contrast to the sooty-black crown of nigri- 

 capillus. RiDGWAY, however, describes it (basing himself 

 upon specimens from eastern Costa Rica and Nelson's de- 

 scription of two specimens from north-eastern Panama) as 

 sooty-black to deep black in M. L bangsi, dark sooty-brown 

 to sooty-black in M. 1. nigricapillus (specimens from Hon- 

 duras, Nicaragua, northern and central Costa Rica; op. cit. 

 p. 613 comp. with pp. 644 and 646). Carriker remarks, 

 that 31. 1. bangsi can be distinguished from M. L nigrica- 

 pillus by the very sooty pileum, which colour is abruptly 

 defined posteriorly. 



About the colour of the back the two authors agree 

 with each other; it is said to be greenish olive, being olive 

 or brownish olive in M. 1. nigricapillus. The inner webs of 

 rectrices are in M. 1. bangsi not at all, or slightly edged with 

 rufous or cinnamon, in M. 1. nigricapillus they are distinctly 

 edged with this colour. 



As to the size we shall find divergencies in the statements 

 by Nklson and Ridgway. 



The measurements of the type (J" ad.) are: 



wing 84; tail 81; culmen 15,6; tarsus 21. 



According to Ridgway the measurements of six adult 

 niales from eastern Costa Rica are: 



wing 79,3; tail 73,3; culmen 17,9; tarsus 18,9. 



The average measurements of eight adult males of M. 1. 

 nigricapillus were stated by Ridgway as follows: 



wing 80; tail 73,9; culmen 18,2; tarsus 19,6. 



The measurements of M. 1. banqsi thus show the fol- 



