What bone is not present in all five fingers

Phalanges (Most distal) - The bones of the fingers. Each finger has three phalanges, except for the thumb, which has two. The phalanges are the bones of the fingers. The thumb has a proximal and distal phalanx, while the rest of the digits have proximal, middle and distal phalanges. so the thumb dont have the middle phalanges