42 



BIRDS OF THE REPUBLIC OF PANAMA PART 4 



tion in tropical jays of interest, but even within a single species, such 

 as the Brown Jay, the level of participation by morphologically im- 

 mature birds seems to differ by region. 



KEY TO SPECIES OF CORVIDAE 



1. Smaller, wing less than 130 mm ; wings and tail extensively blue 2 



Larger, wing more than 160 mm ; wings and tail blacker, with little or no tinge 



of blue 3 



2. Throat and f oreneck dull black ; crown and back of head light blue ; throat 



black. Azure-hooded Jay, Cyanolyca cucullata cucullata. p. 50 



Lower throat, foreneck, and a transverse band between the eyes, extending 

 back narrowly on the side of the crown, light blue. 



Silvery-throated Jay, Cyanolyca argentigula argentigula. p. 48 



3. Foreneck and upper breast deep black ; lower breast and abdomen pale yellow ; 



a line on side of jaw and spots above and below eye light blue. 



Black-chested Jay, Cyanocorax affinis zeledoni. p. 45 

 Foreneck and upper breast dull brownish black, shading to dull white to light 

 brown on rest of lower surface. 



Brown Jay, Psilorhinus morio cyanogenys. p. 42 



PSILORHINUS MORIO CYANOGENYS Sharpe. Brown Jay, Pia-pia 



Psilorhinus cyanogenys Sharpe, Cat. Birds Brit. Mus., vol. 3, 1877, p. 140, pi. 9. 

 (Pearl-Bay Lagoon, Mosquito = Laguna de Perlas, Caribbean coast of Nica- 

 ragua.) 



Psilorhinus mexicanus captus Kennard and Peters, Proc. New England Zool. 

 Club, vol. 10, August 25, 1927, p. 2. (Chiriquicito, Bocas del Toro, Panama.) 



Large; generally dull in color, with long-tipped tail; bill black, or in 

 immatures, yellow; short bristly frontal feathers above base of bill 

 erect. 



Description. — Adult (sexes alike) , head, neck, and upper breast dark 

 sooty brown, becoming dark grayish brown on back and scapulars, in 

 some, paler on the upper tail coverts; wings and tail deep olive-gray, 

 the inner rectrices usually darker; tail tipped rather broadly with white; 

 lower breast changing to grayish brown, in some the shift in color 

 gradual, in others abrupt; undertail coverts grayish white, occasionally 

 nearly white; underwing coverts and scapulars light gray to dull white. 



There is a membranous pouch on the upper breast which, when the 

 bird calls, is inflated so that it is briefly visible. 



Measurements. — Males (9 from Bocas del Toro), wing 178.0-200.0 

 (184.1), tail 175.0-190.0 (187.9, average of 8) , culmen from base 39.6- 

 45.4 (42.8), tarsus 45.3-49.0 (47.5) mm. 



Females (7 from Bocas del Toro), wing 180.0-193.0 (188.4), tail 



