DESCRIPTION OF A NEW GEOTHLYPIS FROM BROWNSVILLE, 



TEXAS. 



BY 

 Robert Ridgway, 



Curator of the Departvienf of Birds. 



Ill Tlie Auk for July, 1891 (p. 316), I>r. J. A. Allen records the 

 ca])ture of a bird at IJrowii.svilh', Tex., wliioli lie ideutitied as (xco- 

 tltlypi,s poliocepliala palpehrolis (i;id,u\v.), and li«^ also miMitioiis a si)eci- 

 ineu in Mr. Seuuett's collection taken at Aldenia, Tiunauli[)as, on the 

 Mexican side of the Rio Grande. I have not had an opportunity to 

 compare the specimens referred to with the tyi)e of (f. )K(lj>ehralis; 

 but the National Museum has re(;ently received from l)i'. Wm. L. 

 Ralph live adult males and one adult femahi of a form of the G. polio - 

 ccphdla group, collected at Brownsville in April and May, 1<S03, and 

 therefore presumably identical with the specimens iiu'utioned by Dr. 

 Allen. 



It requires but a ylance, however, to show that these specimens are 

 not (r. palpchroli.s, which is entirely yellow beneath, while all the 

 Brownsville birds have the sides, flanks and anal region — some of 

 them much the greater portion of the under surface of the body — pale 

 dull bufify, in marked contrast with the clear yellow (;olor of the throat, 

 etc. In this respect they (h>, however, agree very closely with the 

 type of G. poUocephala Baird(fromMazatlan, Mexico), and, were it not 

 for certain constant difterences of coloration andi)roportions, might be 

 <*onsidered the same. Since these constant diffei-ences do exist, it 

 becomes necessary for me to recognize the Brownsville birds as repre 

 senting a local or geographical form, which may be characterized as 

 follows: 



I'ror.'etliiiji.s Naddiiul Musciini. Xdl. XVI, No. H04. 



691 



