Response back from an Expert:
Fred,
The mushroom looks to be /Leucoagaricus naucina/, a member of the family
Lepiotaceae. It should have white spores and a partial veil, but no
universal veil (that leaves a cup at the base & spots or patches on the
top of the cap). The photos are consistent with that. That species is
non-poisonous, despite the name, but inedible.
Hope that helps.
Harold L.
--
Dr. Harold Larsen, Interim Manager - WCRC
Res. Pathologist & Ext. Fruit Dis. Specialist
Colo. St. Univ., WCRC - Orchard Mesa
3168 B 1/2 Road
Grand Junction, CO 81503-9621