A region of the ventral disc of Giardia species (trophozoite stage) where two portions of the same array of microtubules overlap (the microtubule array makes a complete circle and overlaps on itself).
Comment:
Due to the asymmetric nature of the Giardia trophozoite, this term is defined spatially as the trophozoite is viewed from the dorsal side, with the two nuclei dorsal to the ventral disc, and the ventral disc toward the anterior.