As for the size - if I recall right, it was in the 12-15mm length. I wondered about the sericeus call because I have photographed that one before, and it's very shiny vivid green, where this one was very dull in color to where I didn't notice the green until the flashes on the camera went off. Hope that info helps.

but a member of subg. Chlaeniellus which includes C. tricolor (shiniest with vivid color contrasts), C. nemoralis (similar contrast but much duller), C. pennsylvanicus (dorsum more evenly green with less contrast), C. brevilabris (need to see labrum emarginated to be sure), and C. impunctifrons (largest up to 15 mm but pronotum should be broader than shown in image).