This page has images of Heath Fritillary. This is one of the hardest to identify, in particular from Meadow Fritillary and Provencal Fritillary, and my guesses are based on Roger Gibbon's site and he provides two hints: "One identification clue that seems consistent, is that the black shading around both the upf and the unf marginal lunule in s2 is very noticeably heavy. This seems consistent for athalia and conversely not so for other ex-Mellicta species. Of course, enough of the unf has to be visible to see the s2 lunule for this clue to be useful" and "the parthenoides [Meadow] uph discal line is missing or incomplete producing a “gap” where the black lines are usually (but not always) complete in athalia [Heath]."
Two other hints from Guy Hadfield's very useful site seems to be "On upperside and underside [of Meadow Fritillary], the orange submarginal lunule in s. 3 is barely larger than the others in sequence (distinctly larger in heath and very much larger in knapweed)" and " The discal markings in s.1 of the upperside forewing are very variable but never neatly oblique, as in meadow fritillary, not formed into a well-defined dumbell as is common in Provençal fritillary."
To hlep me try to get to grips with these ex-Mellicata fritillaries, I have put together a page of my images of them.
Two other hints from Guy Hadfield's very useful site seems to be "On upperside and underside [of Meadow Fritillary], the orange submarginal lunule in s. 3 is barely larger than the others in sequence (distinctly larger in heath and very much larger in knapweed)" and " The discal markings in s.1 of the upperside forewing are very variable but never neatly oblique, as in meadow fritillary, not formed into a well-defined dumbell as is common in Provençal fritillary."
To hlep me try to get to grips with these ex-Mellicata fritillaries, I have put together a page of my images of them.