These are two mature female mantids. The little brown one is S. californica, and the big green one is S. limbata.
I felt a little uneasy having them so close to each other on the rim of the container, so I held the big one as close as I dared to take this shot. The little one seems especially small. I've definitely seen bigger ones, but I've also seen a limbata male mating with a californica female, and I wonder if there are limbata/californica hybrids running around now.