"Cymochorea leucorrhoa. Leach's Petrel. White-rumped Petrel. Coloration as in the last species (pygmy petrel), with white upper tail-coverts, forming a conspicuous mark; but apt to be lighter - rather of a grayish or even ashy hue on some parts; but easily recognized, whatever the shade of color. Bill and feet black; iris brown." Elliot Coues, 1884

Leach's Petrel

"Cymochorea leucorrhoa. Leach's Petrel. White-rumped Petrel. Coloration as in the last species (pygmy…