Help.

I am 55 days into flowering and just noticed these tiny black mites, about size of tip of pin, all over my leaves. Top and bottoms. Anything I can do this late?

No not really you should have got onto this earlier by regularly checking for mites as they are enemy No.1 .
Get some miticide and bleach and clean the area thorougly after this grow, vacuuming etc.
If you have spidermites top and bottom of leaf at week 55 the damage is done ,harvest is reduced a lot and the finished product smokes up like shit, taste like smoking chopped up seeds.

Damn. That sucks. Thanks for the reply.