A

Elongated spine of axis, natural size.a, Median superior ridge; b, inferior tubercle; c, lateral oblique surface; d, posterior surface; e, lateral tubercle

B

Rudimental spine in the axis of ancient Egyptian

C

Wide bituberculate spine in axis of Saxon, from secondary interment on Bowl's barrow, Wiltshire

D

Axis with acuminate spine

E

Axis with friction facet on superior ridge

F

Spine of axis with long lateral tubercles

G

Arterial foramen, round variety

H

Axis with exserted lateral processes

I

Arterial foramen, ovate variety

J

Axis with lateral processes under cover of upper articular surface

K

Asix with deficiency of outer wall of arterial foramen