Coprinopsis species- Hooghly, West Bengal
Hooghly today - Marasmius rotula (Scop.) Fr. ? : Attachments (3). 7 posts by 4 authors.
Yet, another small mushroom found today (6.10.13), growing on unknown decaying material.
I don't think this is Marasmius rotula. Please check with the images of M. rotula through Google search and you find noticeable differences
Yes, ..., it is not M. rotula, though initially i thought it looked like Tabish Ji's upload. I don't know what is this.
Marasmius species so far in efi.  
To me it looks more like Parasola sp...
May be some Marasmiellus species as per Marasmiellus species- Manipur 

Sorry for the mistake.
Pl. read Coprinopsis cordispora etc. in place of Coprinus cardiasporus etc.