Spring Agaricus (Agaricus bitorquis)?

From July 10th, 2010. Is this what a double ring means? The gills are pinkish, hard to tell in the photo. Coming out of a lawn on Crown St in Crown Heights. Subsequent mushrooms coming out of this lawn also looked the same, with the double edged ring and dark purple-brown spores. The young mushrooms had pink gills and then the older ones had dark brown. Their postage-stamp sized lawn also had these cute fly-agaric lawn adornments!