480 NOTES ON PACHYRIIAMPIIUS ALIJINUCIIA RIDGWAY. 



equal, and loiij^est ; first primary equal to sixth ; tarsus about equal to 

 length of bill measured from the rictus; middle toe considerably shorter 

 than tarsus (slightly less than exposed culmen); feathers of pileum 

 lengthened and broad, forming when erected a full, rounded crest ; along 

 each side of the lower back and rump a conspicuous tuft of pure white 

 cottony feathers. Color (both sexes) grayish above, with glossy black, 

 full-crested pileum, the lower parts, sides of head (below eyes), nuchal 

 collar, lores, and frontlet, white. 



Xenopsaris albinucha (IJuum.). 



rachi/rhamjjhus albitiHcha Buum., P. Z. S., 18G8, 6:55. 



Sp. CHAR. : Adult (No. G7388, TJ. S. National Museum, llio de la Plata, 

 Buenos xVyres ; Dr. H. Burmeister) : Entire pileum (except narrow 

 frontal band), down to the middle of the eyes, glossy black, with a 

 slight bluish luster; narrow frontal band (including nasal tufts), lores, 

 suborbital region, ear-coverts, aud entire under portion of head, neck, 

 and body, white; a rather narrow grayish white nuchal collar (imme- 

 diately below the black pileum) ; hind neck and back uniform ash-gray, 

 the secondaries and rum]> similar but browner; wings, tail, and upper 

 tail-coverts grayish brown, the wing-coverts narrowly and indistinctly 

 margined with whitish, the tertials distinctly edged with white; tail 

 darker than wings, especially towards the end, the shafts pale brown 

 basally ; outer tail-feather broadly edged and margined round end with 

 white. Upper mandil)le, black ; lower, grayish (plumbeous in life?); 

 feet dusky in dried skin. Length (skin), -1.90 ; wing, 2.45; tail, 2.30; 

 exposed culmen, 0.38; tarsus, about 0.48 ; * middle toe, about 0.35. 



To his excellent description, cited above. Dr. Burmeister adtls the 

 following : 



This small bird lives iu the sedj^e of the shores of the Kio de la Plata, near Hiieiios 

 Ayres, and has a souiowhiifc inelaDcholy touiperaiueut, sitting quite still in the same 

 place a long time. 15oth sexes are alike in color, but the color of the male is much 

 clearer, and the white nuchal baud broader aud more distinct. 



Feet considerably mutilated, so that exact measurements can not bo taken. 



