NATURAL SCIENCES OF PHILADELPHIA. 487 



Remarks. In all stages of plumage there is a very considerable 

 range of individual variation, as to both size and markings, though 

 the relative proportion of the parts is very uniform. In two 

 adults, one from Coban, Guatemala, the other from Calovevora, 

 Veragua, the throat is clear bluish-gray, the jugulum similar, 

 rayed with very narrow lines of white. In another specimen from 

 Veragua (a male from Calobre) the colors are darker throughout, 

 the bars on the breast being nearly black ; there is a decided 

 brown wash on the jugulum, and the throat is nearly white 

 centrally. A specimen from Vera Paz, Guatemala, and one from 

 San Pedro, Honduras, have the throat pale-gray, slightly tinged 

 with brown posteriori}' ; the bars on the jugulum white and dull- 

 slate in equal width; while the}' are alike in all other respects 

 also. The specimen from Nanegal, Ecuador, is very similar to 

 these. 



The 3 T oung birds (= M. guerilla, Cass., 1. c.) vary individually, 

 so that only the extremes of their plumage need be described. 

 The darkest example is one from the Volcan de Chiriqui (No. 

 4454, E. Arce). In this specimen the lower parts are deep-buff, 

 marked everywhere with regular, sharply-defined broad bars of 

 dark-brown, these bars as distinct and regular as in the adult, 

 but broader, and separated by wider intervals, the ground- 

 color being light buff. The upper parts of this specimen, how- 

 ever, are about of average character. A Vera Paz specimen 

 is very similar, the onl} 7 difference being that the bars are just 

 appreciably narrower, and the ground perceptibly paler buff. The 

 darkest upper plumage is seen in another Veragua specimen, in 

 which the whole upper surface is a very dark sooty-brown, or 

 blackish-umber, the crown and nape brownish-black ; the wings 

 and scapulars show numerous indistinct bars and transverse spots 

 of pale brown. The lower parts are deep buff, tending to ochra- 

 ceous, but the bars are very distant and confined to the breast and 

 sides. The palest example is one from Guatemala (Choctun, Vera 

 Paz, Jan. 1860), in which the lower parts are buffy-white, entirely 

 immaculate, ; the upper parts are dark grayish-brown, or brownish- 

 dusky, the top of the head darker, the wings and scapulars with 

 the lighter bars and spots nearty obsolete. The latter specimen 

 would probably have assumed the plumbeous phase of the adult 

 dress, and the two others the brown-backed phase. On the right 

 side of this specimen is a perfect feather of the new moult, corre- 



