Paper Wasp Nest

Looks like the start of a wasp / hornet nest ... See here for comparaison on a French nest : http://intruigingnature.photodeck.com/-/galleries/nature-trip-reports/rousson-cevennes-france/rousson-2014/-/medias/906c726f-d49b-4dfd-8dbd-680b14c44940

You should make this an arthropod category, not other, since it is made by an insect.

This appears to be a paper wasp nest. They are individual cells arranged in an umbrella shape and hanging from a single center source. Paper wasps chew vegetation and the mixture with saliva makes a paper like structure. :)