Mergus merganser -- Common Merganser; grand harle, Mergo mayor. Alternate name on piece: Mergus castor [Goosander] "Drawing of specimen / sent from ?Summerleyton 10th Feby 60 / when it was caught in the decoy / weight 3 lbs 3 oz"; layout completely altered in published plate, with main bird relegated to secondary role. Artist's name(s): Gould, John; Richter, Henry Constantine. Conceptual sketch by Gould, modified by Richter--head well finished.