356 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



The construction of an analytical ' ' key " to the various recognizable 

 forms of Sturnella is a most difficult matter, the differences being 

 purelj^ comparative, and therefore not easy to tabulate. The following 

 attempt is far from satisfactory as a means of certain identification, 

 but may be of help in the determination of specimens. 



KEY TO THE SPECIES AND SUBSPECIES OP STHHNELLA. 



a. Breast, etc., bright yellow, relieved by a crescentic or horseshoe-shaped jugular 

 patch of black. ( Adults. ) 

 h. Yellow of throat confined between the maxillse, or if extending over lower 

 edge of the latter the upper parts dark colored, with broad and conspicuous 

 black stripes, 

 c. Larger and paler; wing averaging 117 or more in males, 106 or more in females. 

 d. Larger, with upper parts browner and yellow of under parts lighter {lemon 

 or gamboge) ; wing averaging 122.4 in male, 107.4 in female. (Transition 

 and Upper Austral life-zones of eastern North America.) 



Sturnella magna magna (p. 357) 

 dd. Smaller, with upper parts grayer and yellow of under parts deeper (slightly 

 orange) ; wing averaging 117.1 in male, 106.4 in female. (Western por- 

 tion of Lower Austral life-zone, from coast of Texas to southern Arizona 



and northern Sonora. ) Sturnella magna hoopesi (p. 361) 



cc. Smaller and darker; wing averaging less than 117 in males, less than 100 in 

 females. 

 d. Larger; wing averaging more than 110 in males, 98 or more in females. 

 e. Wing shorter, tail and bill longer; yellow of under parts lighter, more 

 lemon or gamboge (as in S. m. magna) ; auricular region grayish, dis- 

 tinctly streaked; male with wing averaging 111.8, culmen 32.8, tarsus 

 41.4; female with wing averaging 99.1, culmen 28.7, tarsus 38.3. (Humid 

 portion of Lower Austral life-zone, from Florida to Louisiana and 



southern Illinois. ) Sturnella magna argutula (p. .360) 



ee. Wing longer, tail and bill shorter; yellow of under parts deeper, more 

 orange (as in S. m. hoopesi); auricular region buffy white, less streaked; 

 male with wing averaging 116.1, culmen 30.9, tarsus 40.9; female with 

 wing averaging 98, culmen 30.5, tarsus 37.1. (Plateau districts of cen- 

 tral and southern Mexico and Guatemala. ) 



Sturnella magna mexicana (p. 362) 



dd. Smaller; wing averaging 103.6 in male, 94.5 in female. (Coloration as in 



S. m. mexicana, but upper parts browner. ) (Coast district of Vera Cruz 



and southward to Veragua. ) Sturnella magna inexpectata (p. 364) 



66. Yellow of throat covering more or less of malar region; upper parts paler and 

 grayer, more barred than striped, 

 c. Larger, with broader black jugular shield; male with wing averaging 125, 

 tail 75.7; female with wing averaging 110.7, tail 65.8. (Western United 



States and northern Mexico.) Sturnella neglecta (p. 365) 



cc. Smaller, with narrower black jugular shield; male with wing averaging 102.1, 

 tail 65.8; female with wing averaging 93.7, tail 60.2. (Cuba.) 



Sturnella hippocrepis (p. 368) 

 aa. Breast, etc., pale yellow, without any black jugular shield, the latter replaced 

 by dusky spotting. (Young. ^) 



' The young of but few of the forms are represented among the specimens examined; 

 consequently a " key" for their determination is not attempted. 



