Vol. 30, pp. 27-28 February 21, 1917 



PROCEEDINGS 



OF THK 



BIOLOGICAL SOCIETY OF WASHINGTON 



DESCRIPTION OF A NEW SIALIA FROM MEXICO. 

 BY HARRY C. OBERHOLSER. 



Some time ago Dr. Louis B. Bishop sent me for examination 

 four specimens of a bluebird from northeastern Mexico. Upon 

 comparison with abundant material these proved to represent a 

 new subspecies of Sialia sialis. Dr. Bishop has generously 

 donated these specimens to the Biological Survey collection in 

 the United States National Museum, and has permitted the 

 writer to present the accompanying description . This new race 

 may be called: 



Sialia sialis episcopus, subsp. now* 



Chars, subsp. — Similar to Sialia sialis fulva, but blue of upper parts 

 rather darker, and anterior lower parts very much darker. 



Description.— Type, adult male, No. 241,188, U. S. N. M. (No. 23,808 

 Louis B. Bishop) ; Santa Engracia, Tamaulipas, Mexico, December 15, 

 1911 ; F. B. Armstrong. Interscapulum rich blue, between methyl blue 

 and spectrum blue, the feathers with a few rusty edgings ; rest of upper 

 parts, including upper surface of tail, lighter blue, between light methyl 

 blue and salvia blue, the tail somewhat duller, more grayish ; wing-quills 

 terminally fuscous black, shading basally to pale brown, most of the outer 

 webs and all but the marginal half of the inner webs, together with all of 

 the superior wing-coverts, blue like the upper surface; sides of head blue 

 like the pileum, but somewhat paler and mixed with grayish brown ; 

 chin mixed whitish and dull grayish blue; throat, breast, and sides 

 dull chestnut, between chestnut and auburn ; abdomen and crissum 

 white; lining of wing light gray mixed with white and washed with blue. 



Geographic distribution. — State of Tamaulipas, Mexico, north to the 

 lower Rio Grande Valley in central southern Texas. 



Remarks. — -This very interesting new form is in general characters 

 somewhat intermediate between Sialia sialis sialis and Sialia sialis fulva, 

 combining, as it does, the light, more or less greenish, upper parts of the 

 latter with the deep-colored anterior lower parts of the former. It differs 

 from Sialia sialis sialis conspicuously in its lighter, more greenish blue 

 upper surface; and from Sialia sialis guatemalae in its much darker lower 

 * Named for Dr. Louis B. Bishop. 



9— Proc. Biol. Soc. Wash.. Vol. 30, 1917. (27) 



