The Cassius Blue can usually only be seen in Central and Southern Florida and the south of Texas, though occasional sightings are being made in the Big Bend Area of Florida.
This is a Blue with a lot of dark markings on the underside of both wings. It is simialr in markings to the Marine Blue seen in the South West of the country, TX, NM, AZ and overlapping in TX. The difference between these two is an white patch on the underside of the fore-wing very close to the overlap with the hind-wing.