466 Bulletin American Museum of Natural History. [Vol. XXXVI, 



gold or light orange-citrine, more olivaceous, therefore, than the breast of 

 aureatus. This color covers not only the breast but the sides and flanks 

 and to some extent under tail-coverts and is consequently much less re- 

 stricted than the corresponding color in aureatios, the yellow being confined 

 to the upper throat and chin, and center of the abdomen. Sclater's 

 original description (I. c.) reading in part ''pilei cristati plumis rufis, medi- 

 aliter aureis: Subtus fulvo-brunneus, gutture et ventre medio flavescen- 

 tionbus" clearly applies to this bird rather than to the Tropical Zone form 

 in which the whole abdomen and a large part of the flanks are yellow. Fur- 

 thermore, as the appended table indicates his measurements fit the sub- 

 tropical rather than tropical bird, and it is also of importance to note that 

 his type came from the first-named zone. 



Although this bird seems clearly a zonal representative of aureatiis it 

 nevertheless appears to be specifically distinct. Specimens from localities, 

 which like Barbacoas and Ricaurte are in approximately the same latitude 

 and are separated by only a few miles of space but by some 5000 feet of 

 altitude, show no sign of intergradation. On the other hand we have a 

 Bogota skin, labeled by Sclater villosus, which agrees with our Ricaurte 

 specimens in pattern, but has the brown of the underparts of the same 

 shade as in aureatus. It would be most interesting to know whence this 

 specimen came. A male from Inca Mine, Peru, resembles the Ricaurte 

 specimen but is duller below and has the rump paler yellow. 



Cocal, 1; Ricaurte, 3. 



Measurements. 



Name Locality Sex Wing Tail 



(3020o) Myiobius sulphureipygius aureatus Bangs. 



Myiobius xanthopygus aureatus Bangs, Proc. N. E. Zool. Club, IV, 1908, p. 27 

 (Divala, Chiriqui, Panama). 



1 Ex Sclater. 



