148 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



S[ialia] albivcniris "Sclater" Baird, Rep. Pacific R. 11. Surv., ix, 1858, 922, iu 

 text (Guatemala; nomen nudum!) 



Sialia wilsoni (not of Swainson) Sclater and Salvin, Ibis, 1859, 8 (highlands of 

 Guatemala; crit). — Salvin and Sclater, Ibis, 1860, 29 (Coban and Ducfias, 

 Guatemala, resident). — Taylor, Ibis, 1860, 15 (Siquatepeque, Honduras), 

 110 (highlands of Honduras, pine region, alt. 5,000 ft.).— Owen, Ibis, 1861, 

 60 (Guatemala; descr. nest and eggs). — Sclater, Cat. Am. l?irds, 1862, 10, 

 part (Guatemala). — Boucard, Liste Ois. Guat., 1878, 28. 



[Sialia] wilsord Sclater and Salvin, Nom. Av. Neotr., 1873, 4, part (Guatemala). 



Sialia sialis (not Motacilla sialis Linnaeus) Coues, Birds Northwest, 1874, 13, part; 

 Birds Col. Val., 1878, 77, part. — Salvin and Godman, Biol. Centr.-Am., Av(s, 

 i, 1879, 45, j^art (Quezaltenango, ridge above Totonicapjim, Godines, Dueiias, 

 San Geronimo, Tactic, and Coban, Guatemala; Honduras). 



Sialia aziirca Baird, Review Am. Birds, 1864, 62, part (Tactic, Vera Paz, Guate- 

 mala). — Seebohm, Cat. Birds Brit. Mus., v, 1881, 331, part (Guatemala; all 

 of text except synonymy, part). 



[Sialia sialis] var. aziirea Baird, Brewer, and Ridcway, Hist. N. Am. Birds, i, 

 1874, 62, part. 



Sialia sialis guatemalse Ridgway, Proc. U. S. Nat. Mus., v, June 5, 1882, 13 (Guate- 

 mala; coll. U. S. Nat. Mus.). — Reichenow and Schalow, Journ. fiir Orn., 

 1884, 435 (reprint of orig. descr.).— Nelson, Auk, xv, 1898, 161 (highlands of 

 Chiapas) . 



S[ialia] sialis guatemalse Ridgway, Man. N. Am. Birds, 1887, 581. 



Sialia sialis guatemala; ? Ridgway^ Proc. U. S. Nat. Mus., x, 1888, 584 (Segovia R., 

 Honduras; crit). 



[Sialia] guatcmahv Suarpe, Hand-list, iv, 1903, 183. 



SIALIA MEXICANA MEXICANA Swainson. 

 MEXICAN BLUEBIRD. 



Adult male in spring and summer. — Above plain rich smalt blue, 

 brighter and sometimes less violaceous (more ultramarine) blue on 

 rump, upper tail-coverts, tail, and outer webs of primaries;'^ shafts 

 of remiges and rectrices, sometimes also of scapulars and interscapu- 

 lars, back, the upper tail-coverts sometimes with mesial streaks of 

 black; sides of head, chin, throat, upper central (usiuilly also whole 

 median) portion of chest, and breast, uniform blue, slightly paler and 

 duller than bolor of upper parts, the blue gradiuilly fading on abdomen, 

 and flanks into pale gray ; sides of chest and breast and anterior portion 

 of sides chestnut, this sometimes'' extended, more or less broadly, 

 across chest, connecting the two lateral areas, sometimes extending 

 along sides to flanks; under tail-coverts campanula blue, edged 

 basally with pale gray; axillars and under wing-coverts darker cam- 

 panula blue; bill black; iris dark brown; legs and feet black. 



« In only one among ten specimens is there any chestnut on the dorsal region, this 

 having only the lateral anterior portions of the interscapular area slighlly intermixed 

 with chestnut. 



^ In three out of ten specimens, l>ut the connecting band narrow (not exceeding 10 

 mm.) in all. 



