any bone that develops within membranous tissue without previous cartilage formation; e.g. the clavicle and bones of the skull

a smooth prominence of the frontal bone between and above the eyebrows; the most forward projecting point of the forehead in the midline at the level of the supraorbital ridges

the craniometric point midway between the frontal eminences of the skull

the craniometric point in the midline of the forehead immediately above the orbits

the part of the skull that encloses the brain

either prominence of the frontal bone above each orbit

a smooth prominence of the frontal bone between and above the eyebrows; the most forward projecting point of the forehead in the midline at the level of the supraorbital ridges

the craniometric point midway between the frontal eminences of the skull

the craniometric point in the midline of the forehead immediately above the orbits

the part of the skull that encloses the brain

either prominence of the frontal bone above each orbit