Note 69 — THE BONES

1 = Ordinary quadrilateral, approaching prismatic; anterior surface nearly absent to moderate; posterior surface facing directly backward or nearly so. 2 = Lateral prismatic; posterior surface facing backward and inward; medial surface much less in area than lateral; anterior surface narrow to broad. 2a = Relation between medial and lateral surface reversed, the latter being the narrower. 3 = Medial surface fluted. 4 = Lateral surface differentiated into two surfaces. 5 = Lateral surface fluted. 6 = Both medial and lateral surfaces fluted.