Please identify rocks with a number that stays with the specimen in all photos.
Post #9, top rock, could be many curved sections of fossil sea shells showing on the surface of a water worn pebble.
Post #9, bottom rock, onion skin weathering, ex-foliation, maybe from a soil or exposed to sun and frost.
Context is everything. How did they get to where you found them? Were these found with other rounded pebbles in a stream bed or dug out of boulder clay? Were they part of the local bedrock? Did they come from glacial outwash? What part of the valley?