262 BULLETIN 196, UNITED STATES NATIONAL MUSEUM 



Eggs. — There are not enough eggs of this subspecies available to 

 make comparisons, but there seems to be no reason to expect them to 

 vary to any extent from those of the eastern race. The measurements 

 of seven eggs average 20.0 by 16.7 millimeters; the eggs showing the 

 four extremes measure 20.4 by 16.6, 20.0 by 17.2, 19.7 by 16.8, and 

 20.0 by 15.9 millimeters. 



SIALIA SIALIS EPISCOPUS Oberholser 

 TAMAULIPAS BLUEBIRD 



Based on four specimens, sent to him by Dr. Louis B. Bishop, from 

 northeastern Mexico, Dr. Harry C. Oberholser (1917) named the 

 above subspecies in honor of Dr. Bishop and described it as "similar 

 to Sialia sialis fulva, but blue of upper parts rather darker, and 

 anterior lower parts very much darker." He gives a full description 

 of the adult male, and says of its range: "State of Tamaulipas, Mexico, 

 north to the Rio Grande Valley in central southern Texas." 



We seem to have no information on its habits. 



SIALIA SIALIS GRATA Bangs 



FLORIDA BLUEBIRD 

 HABITS 



Outram Bangs (1898) named this bird and gave it the following 

 subspecific characters: "Size of S. sialis sialis; bill larger and stouter; 

 tarsus and foot larger; color of upper parts clearer blue, less purple. 

 In Sialia sialis sialis about smalt blue, and in S. sialis grata about 

 French blue." 



Arthur H. Howell (1932) says that this bluebird is resident "nearly 

 throughout peninsular Florida, from about Lake County south to 

 Royal Palm Hammock." He remarks further: "The Florida Blue- 

 bird lives chiefly in the open pine forests where there is an abundance 

 of rotting stubs suitable for nesting sites. The birds are not at all 

 shy, and their sweet, mellow whistles add charm to the desolate 

 wastes that compose so much of central and southern Florida. The 

 nests are in hollow stubs or fence posts, usually from 4 to 25 feet 

 above the ground." 



SIALIA MEXICANA BAIRDI Ridfiway 



CHESTNUT-BACKED BLUEBIRD 



HABITS 



This handsome race of the Mexican bluebird breeds farther east 

 than but not so far north as the western bluebird, according to the 

 1931 Check-list, "mainly in the Transition Zone from Utah, Colorado, 

 and central western Texas south to Durango and Zacatecas. Winters 



