Hmm...I have some myco growing in my garden under all my plants and it doesn't look like that...more like white blocks of soil with little white tendrils coming from it...
It might be the pics, but that stuff looks fuzzy...which myco is not fuzzy...it is kind of like foamy almost, like solid, hard to explain...does that stuff puff when you touch it...or is it like poking a piece of thin styrofoam? If it is puffy then it is just some sort of mold or what not, but if it is styrofoamy then it is myco living in the soil...