Spittlebug Exuvia - Superfamily Cercopoidea

Froghoppers have incomplete metamorphosis, and their life stages are: egg-nymph-adult. The nymphs are called spittlebugs and they live inside foam that they create. The foam, or "spit" protects them from dessication and predation. Once the nymphal stage is complete, the adult froghopper emerges, leaving a cast skin (exuvia/exuvium) as pictured.

I found lots of spittlebugs in a meadow. The photo shows the remnants of a nymph's shed skin after molting.