Identification: what are these mushrooms?

My SIL has these mushrooms in her Garage/Shed. They are all over the floor and growing like crazy. I tried to look them up but I couldn't find anything like them (maybe I wasn't looking right)
Does anyone know what kind they are?
Are they safe or dangerous?
Why are they growing in the garage/shed in between the boards on the ground and around things?

 

Please, see this:
http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=36949&highlight=peziza+varia

Cheers Harri Harmaja
http://www.fmnh.helsinki.fi/users/harmaja/index.htm

 

for me, Disciotis venosa or big peziza. Remember its smell?

 

I didn't get close to it to smell it. I zoomed in and the cropped the picture. The whole shed/garage smells musky and damp.