BIRDS OF NORTH AND MIDDLE AMERICA. 239 



MIMUS GILVUS GUATEMALENSIS Ridgway. 

 GUATEMALA MOCKINGBIRD. 



Similar to M. g. columbianus , but base of outer webs of primaries 

 (concealed, or mostly so, by primary coverts) white; gray of upper 

 parts slightly browner; wings and tail decidedly blacker, the middle 

 wing-coverts more broadly and abrupth^ tipped with white,** instead 

 of pale gray; white of under parts much less pure, the chest pale buffy 

 gray, the flanks and under tail-coverts more strongly buffy. Young 

 with general color of upper parts paler, middle and greater wing- 

 coverts broadly and abruptly tipped with pure white (instead of nar- 

 rowly tipped with pale buff), tertials broadly margined with white 

 (these markings in 21. g. columbianus pale brownish buff or wood 

 brown, passing mto white terminally), and markings on under parts 

 confined to chest and sides (wanting, or nearly so, on flanks) roundish, 

 instead of longitudinal, and somewhat paler grayish brown. 



Adult maZf'.— Length (skins), 245-255 (249); wing, 108.5-115.5 

 (111.9); tail, 111.5-135.5 (124.4); exposed culmen, 17.5-19.5 (18.4); 

 tarsus, 31.5-34.5 (32.7); middle toe, 21-22.5 (21. g).'' 



Adult female. — Length (skins), 232; wing, 102.5; tail, 108; exposed 

 culmen, 17; tarsus, 31; middle toe, 19.5.^ 



Highlands of Guatemala (San Geronimo; Salama; plains of Zacapa; 

 upper Montagua Valley; Duenas; Jutiapa; Capetillo-Suchitepequez; 

 Nehaj-Quitche) and Chiapas (San Cristobal; Valley of Comitan; 

 Ocuilapa; Ocozucuantla; Jiquipilas) ; Tabasco (Frontera) ; southern 

 Vera Cruz (Coatzacoalcos) ? <* 



fl These white tips, conspicuous in fresh phimage, are obsolete, through abrasion, in 

 worn "midsummer" pkimage. 



'' Four specimens, from Chiapas and Guatemala. 



c One specimen, from Coatzacoalcos, Vera Cruz. 



d I am somewhat doubtful as to the correctness of referring specimens from Frontera 

 and Coatzacoalcos to the present form. All the specimens from the latter locality 

 examined (six in number) are in much more worn plumage than those from Chiapas 

 and Guatemala, therefore the two series are not satisfactorily comparable. Making due 

 allowance for this difference in their condition, the two series agi-ee closely, the 

 Coatzacoalcos specimens being slightly smaller, though this difference may be partly 

 accounted for by wearing away of extreme tips to the primaries and rectrices. Should 

 the correctness of referring the Coatzacoalcos and Frontera specimens to M. g. giiate- 

 malensis be established, the northern part of the range of this form would constitute a 



wedge" separating the range of M. g. laivrencei (in Oaxaca) from that of M. g. gracilis 

 (in Campeche and Yucatan). 



Average measurements of males of the two series are as follows: 



