14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I39 



notes that made up the clear song. This resembled closely that of 

 Thryothorus nigricapillus costaricensis as heard at Almirante, but 

 seemed to be higher in tone and somewhat less varied in repertoire. 



One pair worked busily at a nearly completed nest located near the 

 tip of a leafy branch about 6 feet from the ground in heavy under- 

 growth. This was a ball, nearly round, of palm and other slender 



Fig. 2. — Bay wren, Cucarachero Castano Cabecinegro. 



fibers, with the ends projecting all around as a rough fringe. The 

 entrance was in one side. 



The larger size and paler color of this island population in com- 

 parison with the birds of the adjacent mainland were easily evident 

 in the field. A description of this previously unknown race follows. 



THRYOTHORUS NIGRICAPILLUS ODICUS subsp. nov. 

 Characters. — Similar to Thryothorus nigricapillus costaricensis 

 (Sharpe) 2 but larger, with longer, heavier bill; in color paler brown. 



2 Thryophilns costaricensis Sharpe, Catalogue of the birds in the British Mu- 

 seum, vol. 6, 1881, p. 217. (Valley of the Rio San Carlos, Alajuela, Costa Rica.) 



