Assertion: dinoflagellate's flagellum | /r/AtLocation | orientated groove
Facets:
value: longitudinally
type: MANNER
Source sentences:
text: An acronematic (lacking hairs), posteriorly-directed flagellum is located in a longitudinally orientated groove called the sulcus, and a flattened or ribbon-like flagellum is located in a transverse groove, the cingulum, which encircles the cell in the equatorial region or closer to one pole than the other.