J ^"o2 3 °J BANGS — CHIRIQUI BIRDS 57 



measurements (in millimeters). 



Remarks. — Microcerculus divides into local species, each with a 

 comparatively limited range, in the most astounding manner. So 

 many forms had already been described from near-by localities 

 that it was with some hesitation that I made up my mind to name 

 another, and only after the most careful comparisons, when I 

 found it impossible to refer the bird of the Volcan de Chiriqui to 

 any of them. 



The neighboring species are: — 



M. luscinia Salv. of Santa Fe de Veragua and Santiago de 

 Veragua, south to Panama. 



M. daulias Ridg., Atlantic side of Costa Rica. 



M. orpheus Ridg., Pacific side of Costa Rica. 



M. philomcla (Salv.), Guatemala. 



From all of these M. acentetus differs much, except from M. 

 orpheus, which is its nearest ally. From this species the new 

 form can be told by its wholly unbarred back, rump and upper 

 tail coverts, its much less varied under parts, and shorter bill. 



Cyanolyca argentigula(Lawr.). 



Eleven specimens, adults of both sexes, Volcan de Chiriqui, 

 9000 feet, June. 



This jay and the following species appear to be extremely local 

 in their distribution. A small colony of C. argentigula was found 

 at the spot where these were taken, but the species was seen 

 nowhere else on the Volcan de Chiriqui. On the Caribbean slope 

 Mr. Brown took the three specimens of C. cucullata, but saw no 

 more of that species. 



