The chondrocranium of a 23‐mm. necturus

Abstract This study is based on a wax model reconstructed from serial sections stained with basic fuchsin and picro‐indigo‐carmine. It shows: 1) that the columna ethmoidalis and planum basale are chondrified at this stage; 2) that a cartilaginous antorbital process is present; 3) that the stapedial plate is cut out from the wall of the otic capsule; 4) that the so‐called crista trabecularis is an independent element homologous with the sphenolateralis of the Anura; 5) that the fourth visceral arch is not present and that the fifth is still in the precartilaginous stage; and, 7) that there is no evidence that a pro‐occipital vertebra is formed.