They were growing individually and in clumps.
Billy thinks it might be Clitocybe candida.  Checking the description on the Internet I tend to agree.  I am finding a lot of mushrooms, this year, that are not listed in my guides. 

On 10/19 I found some prime condition once in my back yard.  Roger Philips rates it as inedible.  Others as unknown.  Alexander H. Smith rates it as edible but not worth the effort.  I decided to give them a try.  They looked so fat and meaty.  Smelled good and tasted good raw.  I cooked some up with potatoes, onions, garlic and olive oil.  I like the taste better then Chicken of the Woods.  That is not saying much :o)
If I have no ill effects, I will have to try them again.  I got absorbed answering e-mail and burned then a little bit :o)

Some had a darker area in the center of the cap.  Somewhat visible in the lower mushroom.  The largest had a cap of 3".  No ring on stem.  Produced white spore print.  Smells and tastes like the button mushroom you buy in the store.

Gills are white.

If you recognize it, please let me know.