Polygonia comma form of comma is frequently confused with the dark form of the question mark ("P. interrogationis"), but the two can readily be distinguished by the shape of the comma mark on the underside. The pale form is easily confused with the satyr comma ("P. satyrus"), which usually occurs north and west of the eastern comma's range. They can be distinguished by the upperside color, which is orange brown in the comma and tawny yellowish brown in "P. satyrus"; by the underside pattern, which tends to be mottled in the comma but appears to be more longitudinally streaked in "P. satyrus";
What Bird is That? according to their usual habitat. The accompanying text included brief notes on distribution, breeding and behaviour. While initial sales were poor, history tells us that Cayley had accurately discerned a market need and successfully responded to it. During WWII sales accelerated and Cayley’s first collection, reprinted time and time again, eventually became a household name among birdwatchers and the book was recognised as an Australian classic. The original sponsorship of "What Bird is That?" proved a great investment for the Gould League, who benefited from the sale of its numerous reprints and revised editions. By 1960, it was rated the