Marshall (1942) Basileuterus delatirii Lake Olweya - 1800, 1801 taken in clump brush over pool edge lake NE camp where dense [illegible] forest goes clear to lake. Very lone. Apr 6 W slope Los Esmeriles 2261 shot in tall growth brush at trail-side or W slope. Cover where geocoryx, Melozone, etc also found. Volcan de Santa Ana 2412 x 2413 taken in brush patches under tree growth in flat-land forest NE Base Cerro de los Narajos on same ground with B. culicivorus. Paired, it's singing. Also in coffee bushes back of camp when shaded by cypress etc. Chilata noted. Basileuterus culicivorus V de Santa Ana Pairs males singing in brush patches under forest cover NE base Cerro de los Narajos - very common pairs close together. Also in shaded coffee brushes.