I found these Agaricus in Ukiah but I could not positively ID them. They look a bit like A. californicus but they do not stain yellow on cutting, bruising, OR with a drop of KOH on the cap. They have not much smell, but I'm not the greatest nose around. I suppose they could have a very faint phenol scent but i wasn't sure. They did not smell almondy. They were growing in grass. The gills are not pink,but kind of whitish to buff. A fellow observer from BAMS suggested A. Californicus. Another suggested A. arvensis due to the cogwheel pattern evident in the ring. I also wondered if they may be A. hondensis.