THE DWARF OOWBIRD. 443 



foster parents and seeks the company of its own kind, which gather in small 

 bands and rove from place to place. Later in the season, about the latter part 

 of October, these gather into larger flocks, associating at this time with other 

 congenial species, and shortly after they -'eturn to their winter homes in Mexico. 



In general appearance and shape t!ie eggs of the Dwarf Cowbird resemble 

 those of the preceding species, and the same description will answer for both; 

 but they appear on an average to be somewhat less heavily spotted, which gives 

 them a lighter appearance, and they are also considerably smaller. 



The average measurement of thirty-seven specimens in the United States 

 National Museum collection is 19.30 by 14.99 millimetres, or 0.76 by 0.59 inch. 

 The largest egg- in this series measures 20.57 by 15.49 millimetres, or 0.81 by 

 0.61 inch; the smallest, 18.03 by 13.74 millimetres, or 0.71 by 0.54 inch. 



The type specimens, No. 20178 and 20179 (PI. 6, Figs. 7 and 8), both in 

 the Bendire collection, were taken by the writer on Rillito Creek, near Tucson, 

 Arizona, the first and smaller on June 20, 1872, from a nest of the Black- 

 throated Sparrow, with only a single egg of its own, incubation having com- 

 menced; the second, on July 19,1872, from a nest of the Least Vireo, containing 

 also two of its own eggs, which were fresh. They represent about the usual 

 amount of markings, and the last-mentioned specimen is above the average size. 



172. Callothrus robustus (Cabanis). 



EED-EYED COWBIRD. 



Psarocolinus ceneus Waglbb, Isis, 1829, 758. 



Callothrus robustus EidgwAY, Manual of North American Birds, 1887, 589. 



(B _, O — , R 259, 315, U 496.) 



Geographical range : Mexico and Central America, north to southern Texas, south 

 to Panama. 



The breeding range of the Red-eyed or Bronzed Cowbird, a larger and 

 darker- colored species than the two preceding, coincides with its geographical 

 distribution in the United States, and extends, as far as known, northward and 

 eastward only to Bexar County, Texas, where Mr. H. P. Attwater reports it as a 

 rare summer resident near San Antonio, and where he found one of its eggs in 

 the nest of a Bullock's Oriole. 



We are indebted to Dr. James C. Merrill, United States Army, tor the addi- 

 tion of this interesting species to our fauna. He first recorded it in the Bulletin 

 of the Nuttall Ornithological Club (Vol. I, 1876, p. 88), as an abundant summer 

 resident in the vicinity of Fort Brown, Texas. A full account of the breeding 

 habits of this species by Dr. Merrill may be found in the above-mentioned Bulletin 

 (Vol. II, 1877, pp. 85-87), from which I extract the most interesting notes: 



"My first specimens were taken at Hidalgo, on the Rio Grande, 70 miles 

 northwest of Fort Brown, where, however, they are not so abundant as lower 

 down the river. Here they are common throughout the }'ear, a small propor- 



