Hi Greg,
What aspects of these patterns causes you to conclude they are spiders? They appear to my eye more like elevated walls, though lacking the rectilinearity typical of those you've posted. Still, I've seen comparable wall-like formations elsewhere on Mars, and it never occured to me that they were comparable to spiders.
Also, I see scant evidence of the dendritic patterns which apparently are a primary characteristic of spiders.
It seems these questions might be especially pertinent, since spiders have previously appeared exclusively to be a south circumpolar phenomenon.
Wil
