“Subcaudals” refer to the scales under the tail, not the anal scale.
The term ‘caudal’ refers to the tail. It derives from the Latin word ‘cauda’, which means ‘the tail of an animal’. Hence subcaudal is ‘beneath the tail’.
The external opening of the cloaca (the vent) marks where the body ends and the tail begins. The anal scale is attached forward of this opening. It is therefore on the stomach of an animal and not on its tail. So the anal scale is NOT a subcaudal.