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 eJges. 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; cuhnen 21; greatest depth of bill 16; 



greatest width of under mandible 14 ; tarsus 23. 



Average dimensions of four adult females of Gairaca cceralea eurhyncha 



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



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



21.5. 

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



Arizona): wing 84. 5; tail 65.2; culmen 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 

 pany ing figure (fig.!4a); 

 it is lighter and less 

 buffy on lower parts, 

 particularly on breast 

 and neck. This species 

 is probably a resident 

 of central Chiapas and 

 Fio. 14. a, Guiraca chiapens^. perhaps bears the same 



b, Guiraca ccerulea eurhyncha. relationship to Guiraca 



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

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

 beaks w r ere 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. 



Grallaria ochraceiventris sp. nov. Buff-bellied Ant Thrush. 



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



