What is the name of this black-ochre striped snake?
Great find!  Based on the picture and location, I believe this is the Corsican grass snake (Natrix natrix corsa).  It is a pretty rare subspecies, and is listed on Annex IV of the European Union Habitat and Species Directive.  Worth mentioning that it's nonvenomous.  



Photo cred to Frank Deschandol/Philippe Sabine

Unfortunately, I was not able to find too much more info on this subspecies.  I know Natrix natrix are pretty widespread throughout Eurasia, but this subspecies is much more restricted.