258 SYSTEMA TIC SYXOPSTS. — PASSERES— OSCIXES. 



S. mexica'na occidenta'lis. (Lat. mexicana, of Mexico; occidentalism of the Occident or 

 setting sun, i. e., Western.) Townsend's Western Bluebird. Mexican Bluebird. 

 (J, adult : Eich azure-blue, including head and neck all around; a patch of purplish-chestnut 

 on upper back, more or less completely divided into a pair of patches ; breast and sides rich 

 chestnut ; belly and vent dull blue or bluish-gray. Bill and feet black. Size of the last 

 species. 9, and young: Changes of plumage coincident with those of the Eastern bluebird. 

 Immature birds may usually be recognized by some difference in color between middle of back 

 and other upper parts, and between color of throat and of breast ; but birds in the streaky 

 stage could not be determined if the locality were unknown. In typical adult $ , the dorsal 

 patch is restricted, or broken into two scapular patches with continuous blue between ; the 

 chestnut of breast sometimes divides, permitting connection of the blue of throat and belly (see 

 anahelcB below). Specimens with little trace of the dorsal patch are scarcely distinguished from 

 those of S. sialis, in which there is much blue on the throat, the grayish-blue of the belly, in- 

 stead of white, being a principal character. Pacific Coast region of the U. S. and British 

 Ccdumbia. E. occasionally in migrations to Utah, Nevada, New Mexico, etc. Abundant ; habits, 

 nest, and eggs identical with those of ^S*. sialis. S. occidentalis Towns., Journ. Acad. Nat. Sci. 

 Philada., vii, 1837, p. 188. S. mexicana occidentalis Eidgw., Auk, Apr. 1894, pp. 151, 1.54; 

 A. O. U. List, 2d ed., 1895, p. 322, No. 767 ; as subspecifically distinguished from the typical 

 Mexican form with which it had before been considered identical, and from the following : 

 S. m. baird'i. (To S. F. Baird.) Chestnut-backed Bluebird. Baird's Bluebird. 

 In typical adult $ the patch of chestnut on the back forming a single solid area, well defined 

 against blue surroundings. Eocky Mountain region of the U. S., S. into Mexico. Auk, Apr. 

 1894, p. 151, p. 157 ; A. 0. U. List, 2d ed., 1895, p. 323, No. 767 a. 



S. m. anab'elae. (To Mrs. Anabel Anthony, wife of W. A. Anthony.) Anabel's Blue- 

 bird. San Pedro Bluebird. Chestnut of breast divided by blue of throat, and thus re- 

 stricted to lateral pectoral patches ; that of scapulars almost entirely absent ; size at a 

 maximum. San Pedro Martir Mts. of Lower California. Anthony, Proc. Cala. Acad. Sci., 

 2d ser., u., Oct. 1889, p. 79 (see Key, 4th ed., 1890, p. 897); A. 0. U. List, 2d ed., 1895, 

 p. 323, No. 767 h. (This and the last subspecies recognized by name in no former ed. of the 

 Key, being both included under Mexicana, with express statement, however, of their respec- 

 tive peculiarities.) 



S. arc'tica. (Lat. arctica, arctic; Gr. apKTos, arctos, a bear; i. e., near the constellation Ursa 

 Major.) Arctic Bluebird. Eocky Mountain Bluebird. ^, in perfect plumage: 

 Above azure-blue, lighter than in the two foregoing, and with a faint greenish hue ; below, 

 paler and more decidedly greenish-blue, fading insensibly into white on the belly and under 

 tail-coverts. Ends of wing-quills dusky; bill and feet black. Larger; length 7.00 or more; 

 extent 13.00 or more ; M'ing 4.50 ; tail 3.00. 9 '■ Nearly uniform rufous-gray, lighter and 

 more decidedly rufous below, brightening into blue on rump, tail, and wings, fading into w^hite 

 «m belly and crissum ; a whitish eye-ring. Young : Changes parallel with those of the other 

 species. Birds in the streaky stage may be known by superior size, and greenish shade on 

 the wings and tail. N. America from the W. portions of the Great Plains and E. spurs and 

 foothills of the Eocky Mts. to the Pacific, chiefly in high open regions, abundant ; resident 

 southerly, migratory N. to Great Slave Lake, S. into Mexico. Habits thdse of the otliers ; 

 nesting the same, but eggs larger, about 0.92 X 0.70. 



CYANEC'ULA. (A diminutive form of Gr. Kvaveos, kuaneos, Lat. cyaneus, blue : as we 

 should say, "bluet.") Bluethroats. Bill much shorter than head, slender, compressed 

 throughout, acute at tip, with obsolete notch (as in Saxicola, but slenderer). Feet, as in Sax- 

 icola, long and slender ; tarsus much longer than middle toe and claw ; lateral toes of unequal 

 lengths; outer longer, but tip of its claw falling short of base of middle claw; claws little 

 curved, the hinder fully as long as its digit. Wings long (less ,so than in Saxicola), pointed by 



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