Brown Argus , Gunners Park (all of the above), Essex 26th July 2008
Note the lack of spot on the lower forewing and the two spots close together on the upper edge of the hindwing: this confirms seperation from the similar female Common Blue.
Brown Argus, Barling Magna Millennium Wildlife Park, Essex 17th August 2008
Compare the underwing patterns of the Common Blue on the left and the Brown Argus on the right. The Brown Argus has two close spots, one about double the size of the other whilst the Common Blue has it's two spots spread apart and are of similar size. In the row of spots the Brown Argus second rear spots in significantly lower than that on Common Blue. Also note the underside of the outer wing: the Brown Argus has bright orange spots whilst the Common Blue does not.