Unidentified

I am by no means an expert when it comes to mushrooms.  I have learnt a lot though and am getting quite good with general identification.  There are some however, usually the small ones, which are incredibly difficult to identify!  There are an estimated 5.1 million different species of fungi in the world, but still, only a very small percentage have actually been described.  

Here's one I have no idea about!

Small, chocolate brown all over, found on unimproved grassland.

If you know what it is, please let me know!