Not a new funding round as we reported earlier this morning. Twitter bought geolocation services startup Mixer Labs late last year, but the amount wasn’t disclosed: now in a new SEC filing it is slightly more clear: the filing says it “raised”  a relatively tiny round of $5.2 million in series E (fifth round) of funding, but also discloses it is in relation to a recent acquisition, in this case Mixer Labs. It is likely a mix of some cash, plus equity in the company for Mixer Lab founders; the startup hadn’t raised any venture money. In late August last year, Twitter said it would introduce an opt-in feature that would make it easier for users to add their location to their Tweets and this acquisition is supposed to plug into that initiative.