78 BULLETIN 17 9, UNITED STATES NATIONAL MUSEUM 



October or early in November, rearing only one brood ; so that these 

 ten nests found late in December were of birds that had lost their first 

 nests. Probably three-fourths of the lost nests of Milvulus are 

 abandoned in consequence of the confusion caused in them by the Cow- 

 birds." 



Ten out of nineteen sets of eggs of this flycatcher in the United 

 States National Museum contain eggs of this cowbird. The only nest 

 of this flycatcher that I have seen is in the Thayer collection in Cam- 

 bridge, It was taken at Punta Gorda, British Honduras, on March 

 31, 1907, by N. Karslund and contains four eggs. It was built in a 

 small pine, 12 feet from the ground. On a foundation of coarse 

 weed stems and coarse grasses is a layer of stiff, black rootlets; above 

 that is the nest of grasses, coarse vegetable down, weed tops, seed 

 and blossom scales, and vegetable rubbish of various kinds ; it is lined 

 with a fine grade of usnea ; its outside diameter is 5 by 4% inches, and 

 the inner diameter is about 3 inches; the external depth is from 2 to 

 214 inches ; and the inner cavity is only three-quarters of an inch deep. 



George K. Cherrie (1892), in his list of birds found near San Jose, 

 Costa Rica, says that "a nest with three fresh eggs, taken by Don 

 Anastasio Alfaro at Tambor, Alajuela, May 2, 1889, was placed in a 

 small tree, about ten feet from the ground. The parent bird left 

 the nest only very reluctantly and not until almost within the grasp 

 of the collector. The nest is constructed of a mixture of small dry 

 grass and weed stems and soft dry grass rather compactly woven 

 together, with a lining of a few fine rootlets." 



Eggs. — The four eggs in the Thayer collection, the only ones I have 

 seen, are short-ovate and only slightly glossy. They are pure white 

 and rather sparingly marked with spots and small blotches of dark 

 brown, dark "chestnut-brown" or "seal brown" and various shades 

 of "quaker drab" or "brownish drab." 



Hudson (1920) says that "the eggs are four, sharply pointed, light 

 cream-colour, and spotted, chiefly at the large end. with chocolate." 



Baird, Brewer, and Ridgway (1905) say: "An egg of this species 

 obtained bv Dr. Baldamus, from Cayenne, exhibits a strong re- 

 semblance to the egg of the common Kingbird. It has a clear white 

 ground, and is spotted with deep and prominent markings of red 

 and red-brown. They are of an oblong-oval shape, are tapering at one 

 end, and measure .90 by .68 of an inch." 



Evidently the eggs vary considerably in shape and coloration. The 

 measurements of 50 eggs average 22.1 by 16.2 millimeters; the eggs 

 showing the four extremes measure 25.2 by 17.3, 23.1 by 18.0, 20.0 

 by 15.3, and 20.7 by 15.0 millimeters. 



Plumages. — As I have seen no very young specimens of this species 

 and not enough molting birds to give a clear idea of the plumage 



