Assertion: pit viper's pit | /r/HasProperty | lined with membrane
Facets:
Source sentences:
text: The labial pit found in boas and pythons lacks the suspended membrane and consists more simply of a pit lined with a membrane that is similarly innervated and vascular, though the morphology of the vasculature differs between these snakes and crotalines.
text: Internally the organ forms a small pit lined with membranes, external and internal, attached to the trigeminal nerve.