sagittal plane n.
A longitudinal plane that divides the body of a bilaterally symmetrical animal into right and left sections.
This margin lies in the sagittal plane of the body, whilst the two flat sides are right and left.
One of the annular constrictions is constantly in the sagittal plane (separating the right and left halves of the shell).
The caudal and sternal ribs, which are opposed in the sagittal plane, are simple, whilst the two lateral ribs are forked.
The stomodaeum lies in the sagittal plane, the funnel and tentacles in the transverse or tentacular plane.
The intermediate is the sagittal plane or median plane (halved by the crossed principal and sagittal axes).
The sagittal plane of the valve of the auxospore is at right angles to the plane of the valve of the mother cell.