500 BIRDS OF THE REPUBLIC OF PANAMA PART 3 



leaves and stems wound loosely around the branch for a distance of a 

 meter. The nest cup was in a somewhat enlarged portion below the 

 center, with the opening 60 mm wide, about 130 mm in diameter, and 

 the cavity about 60 mm deep. The whole was frail and unfinished in 

 appearance. It held two eggs, one of which was broken. The other is 

 subelliptical in form, with the entire shell suffused with dull reddish 

 brown as a heavy covering over most of the surface, except for the 

 lower quarter. It measures 20.4x14.4 mm. Another nest, collected 

 by Storrs Olson and J. Wiese, May 9, 1966, at Mile 12, between 

 Gamboa and Summit Gardens, Canal Zone, hung pendant from the 

 tip of a branch 2 meters above a small stream. It is slender and 

 cylindrical, about 80 cm long by 10 to 15 cm in diameter, made of long 

 bits of rootlets, grass stems, and other slender fibers, through which 

 dry leaves and other bits of vegetable material are interspersed, the 

 whole interlaced loosely but firmly, and narrowed at the lower end to 

 a tail-like streamer. Immediately above this is an opening in the side 

 to the ball-shaped nest, which is wholly enclosed. In this there was a 

 fledgling bird with wings beginning to develop, and an addled egg. 

 This egg, closely similar in color, pattern, and subelliptical form to 

 the one taken by Goldman, measures 19.7 X 15.2 mm. 



As a species this flycatcher ranges from southern Mexico through 

 Central America to central Colombia and northwestern Venezuela. 



The race fratercuhts, described from the Santa Marta region of 

 northern Colombia, differs only slightly from the nominate form. In 

 average size it is somewhat smaller, and in Colombia is somewhat 

 paler buff on the lower surface, with the dark streaking on the breast 

 heavier. Those found from Costa Rica through Panama, while in size 

 they average about like those of Colombia, are variable in color 

 and marking of the lower surface. For comparison there is included 

 a set of measurements of the nominate form, 0. m. mexicanus: 

 Males (13 from Veracruz, Tabasco, Oaxaca, and eastern Guatemala), 

 wing 86.7-93.6 (89.8), tail 70.5-76.0 (73.4). culmen from base 25.2- 

 29.3 (27.8), tarsus 17.4-18.7 (17.9) mm. 



Females (7 from Veracruz. Tabasco, Oaxaca, and eastern Guate- 

 mala), wing 79.8-83.5 (81.3), tail 65.0-69.6 (67.1), culmen from 

 base 24.8-26.1 (25.5, average of 6), tarsus 17.0-18.0 (17.2) mm. 



De Schauensee (Birds of South America, 1966, p. 359) has in- 

 cluded all of the Royal Flycatchers from Mexico through Panama 

 as races under the species name Onychorhynchus coronatiis (Miiller), 

 a proposal that should have further study where the two groups, 

 mexicanus and coronatus. meet in southeastern Colombia and eastern 



