Can someone identify this mushroom?
This is most likely a member of the genus Amanita, judging by the vellum traces on the cap, remains of a ring (2nd photo, under your thumb), free white gills. 

What we are missing for a better id is the base: is there a volva, a bulbous end...? Please dig out your mushrooms instead of cutting them off.

Also, the colour is significant: are there pinkish tinges (-> A. rubescens?) or is it just brown?