Fungus?

Yesterday I found a small collection of spots on the edge inside my Nikon 70-210 f/4 Series E lens. It might be fungus, or dust, or something else. (Or I'm just being paranoid). Any ideas as to what it is? I don't really know what fungus could look like.

(The pictures make it seem much larger than it actually is.)

Hard to say from that picture but it looks too concentrated to be dust and may be the beginnings of an infestation..
Tons of info via google.

http://throughavintagelens.com/2010/06/lens-fungus/

I should mention all the fungus I've seen has been the spider web looking type.
This type is easy to identify as fungus.

Yours looks a bit harder to tell at this point.