Hatschek's pit noun1 •A deep ciliated fossa on the dorsal midline of the buccal cavity in lancelets.[…] that most authorities now accept the possibility that Hatschek's pit might be the homologue - in some ancestral form, the precursor - of Rathke's pouch, and so of the adenohypophysis. — 1974 formsHatschek's pits
