Page:Auk Volume 37-1920.djvu/180

108 Cory, New Species and Subspecies of Tyrannidce. [ jEm birds prove that in central western Peru the Killdeer breeds in December and January. The localities in question are only about 450 miles apart. I know of no marked seasonal difference between them, and am quite at loss to account satisfactorily for this variation in nesting dates. Possibly the uniform climate, both as regards temperature and rain- fall, prevailing on the coast of Peru, militates, among Killdeer, as it apparently does among the Cormorants and Pelicans of the Guano Islands off the coast, 1 against the establishment of a definite breeding season. Or we may have here a case similar to that of the Brown Pelicans in Florida which on the Gulf coast begin to nest in April and on the Atlantic coast in November. Further collections and field studies are required to settle this interesting question Amer. Museum Nat. Hist., N. Y. DESCRIPTIONS OF A NEW SPECIES AND SUBSPECIES OF TYRANNIDtE. BY CHARLES B. CORY. Todirostrum beckeri sp. nov. Type from Base of Serra da Lua, near Boa Vista, Rio Branco, N. Brazil . Male, No. 49,347, Field Museum of Natural History. Collected by R. H. Becker, March 24, 1913. Description. — Similar to T. sylvia schistaceiceps (Sclater) and T. sylvia griseolum Todd, but differs from either in the shorter wing, in having the black loral stripe bordered below by a buffy streak, and above by a con- spicuous buffy stripe extending from the base of the upper mandible to above the eye. Base of crown and nape olivaceous; greater wing coverts edged with buffy yellow or pale orange yellow; middle wing coverts tipped with same; lesser wing coverts edged with olive green. Measurements. — Wing, 45; tail, 30; bill, 13 mm. 1 Habits and Economic Relations of the Guano Birds of Peru, by Robert E. Coker,. U. S. Bureau of Fisheries, Proc. U. S. N. M., 56, 1919, pp. 449-511.