I am assuming this is a Myxo (Trichia / Hemitrichia ) but not completely certain as they have not progressed to the usual sporangium state that I associate with the normal transition process. The substrate does not seem of particular importance, as you can see from the attached images, all found in close association to each other.
Can anyone confirm or otherwise.

[attachment=3]DSC_0032.JPG[/attachment]

[attachment=2]DSC_0035.JPG[/attachment]

[attachment=1]DSC_0039.JPG[/attachment]

[attachment=0]DSC_0041.JPG[/attachment]
thanks
John