Pyrgus carlinae - Carline Skipper

Pyrgus-carlinae--carline-skipper | PTKbutterflies
Pyrgus-carlinae--carline-skipper | PTKbutterflies

This Pyrgus is typified by a "C" shaped upperside forewing cell spot, and I seem to have seen this more often than some of the others.

The white marinal hindwing spot in S4 is also said to be prominently rectangular.. these butterfly images, from the Italian and French Alps do show these features.