2-1/4" x 3-3/4" mounted on card: 3-1/2" x 4" (very good condition; see scan for details)
 
NOTE: Considering the low negative numbers written on the back, these would seem to be very early CDVs by Pomfrey & Oneal.  One of the little girls is ID's as Mary Oneal (written without apostrophe as is the photographer). On her image, the name of Pomfrey is crossed out which may indicate that Oneal took this particular image of (what may be presumed to be) his daughter.