Towards evening  of 6/14/09 I checked the oak leaf pile where I found Blewit last fall.  I found this group of mushrooms growing.  The largest cap was 3.5".  The thickest stem was 5/8".

Top.  Slight umbo in center.

Gills are attached and very closely packed together.

Side by side, with the youngest second from left.  The longest stem was 4.5"

Section of stem.  White mycelium at base of stem.

Spore print was white.  largest spore measured 9.6 x 5.8 microns.

I believe it is a Collybia specie.