[Ken Burgess]

The remains of the veil on the cap are the most immediately apparent difference. Amanita pantherina has pure white spots, whereas in Amanita excelsa var. spissa, which yours specimens are, the veil is greyish.

Although the edge of the cap may appear lined in your photos, this is more because the cuticle is slightly radially fibrillose at the edge. A striate margin usually relates to the gills underneath, with the spacing of the striations matching up with the underlying gills. This is clearly not the case for your specimens.

You have already picked up on the striate ring, which is characteristic of Amanita excelsa var. spissa and not Amanita pantherina. The volva is also not very noticeable in the former but quite distinctive in the latter species.

Hope that helps.

Ken