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. 



