Lateral lacunae

The lateral lacunae are small openings that communicate with irregularly shaped venous spaces (venous lacunae) in the dura mater near the sinus.

There are usually three lacunae on either side of the superior sagittal sinus: a small frontal, a large parietal, and an occipital, intermediate in size between the other two. Most of the cerebral veins from the outer surface of the hemisphere open into these lacunæ, and numerous arachnoid granulations (Pacchionian bodies) project into them from below.