Agraulis vanillae

This is the Gulf Fritillary, sometimes called the Passion Butterfly. (Family Nymphalidae, sub-family Heliconiinae.) Earlier this month and throughout most of September there were quite a few around here. Evidently, they aren't easily startled, and were fairly easy to photograph. They fly pretty high above the ground compared to lots of other butterflies I've studied.

Here's a close up of the underside of both the upper and lower wings. Notice the dark 'eyespot' on the third and largest white oval marking on the lower wing. A very distinguishing characteristic.