I'm thinking this could turn out to be a Tubifera.sp, it's on a big log so couldn't take it home, hope the snails leave alone.
These look like Stemonitis.sp forming, notice other species of mycocycete already on the wood and the stemonitis has just formed over them, (there were masses of both).
This was one of those lucky finds were the myxomycete is in the process of forming fruit bodies, poor photo but i hope you can see the vein like structure linking all parts as it crawls into position, hope this dosn't get trod on as the result tommorow will be interesting (at the moment i'm thinking it may not be a fuligo despite the colour (could be wrong)).
Cheers J.P.