62 



Nelson — Description of New Birds from Mexico. 



and throat whitish at base and dull buffy on outer half; feathers on sides 

 of chin, throat, and under surface of neck and breast dull brownish with 

 dingy buffy edges. Rest of lower parts much lighter, the feathers with 

 dark shaft lines and bordered along edges by pale grayish and buffy. 

 Dimensions: Wing 90; tail 72; eulmen 21 ; greatest depth of bill 16; 

 greatest width of under mandible 14 ; tarsus 2o. 



Average dimensions of four adult females of Guiraca cozrulea eurhyncha 

 (from central and southern Mexico) : wing 87.5 ; tail 67 ; eulmen 17.2 ; 

 greatest depth of bill 12.9; greatest width of under mandible 11.2; tarsus 

 21.5. 



Averages of four adult females of Guiraca c. eurhyncha (from southern 

 Arizona): wing 84.5; tail 65.2 ; eulmen 16.9; greatest depth of bill 13.1; 

 greatest width of under mandible 11 ; tarsus 21.4. 



The type of G. chiapensis is in worn breeding plumage and is very sim- 

 ilar in color to a female 

 of eurhyncha taken at 

 the same season in 

 southern Arizona, but 

 may be distinguished 

 at once by its huge bill, 

 as shown in the accom- 

 panying figure (fig. 14 a); 

 it is lighter and less 

 burly on lower parts, 

 particularly on breast 

 and neck. This species 

 is probably a resident 

 of central Chiapas and 

 perhaps bears the same 

 relationship to Guiraca 

 eurhyncha in size and range that Passerina sumichrasti does to /'. parellina. 

 In the district where the type of G. chiapensis was taken, Blue Gros- 

 beaks were common and probably were all or nearly all of this species. 

 Unfortunately, not having distinguished the latter from eurhyncha at the 

 time of our visit, we failed to secure other specimens. 



Fig. 14. — a, Quiraca chiapensis. 



/., Quiraca coerulea eurhyncha. 



G-rallaria ochraceiventris sp. nov. BufF-bellied Ant Thrush. 



Type No. 156013, U. S. Nat. Mus., Biological Survey Coll. Ad. cf, San 

 Sebastian, Jalisco, Mexico, March 16, 1897. Collected by E. W. Nelson 

 and E. A. Goldman. 



Distribution. — Heavy forests in western Jalisco, and perhaps elsewhere 

 in western Mexico north of Tehuantepec. 



Description of type. — Feathers of crown and back olive-brown, shaded 

 with fulvous, and narrowly margined with black ; sides of crown, back of 

 orbits, and nape olive-brown with a dark ashy shade most marked on 

 sides of crown ; forehead paler or more fulvous brown. Tertiaries and 

 secondaries dull rusty brown ; outer vanes of primaries shading from dull 



