I think that the text in Keiti contains a sequence of glyphs leading up to this glyph:

Ea9-31	Eb1-6	Eb1-17	Eb1-32	Eb1-41

If I am right, then the glyph Eb1-41 presumably shows the same type of glyph as that in Eb1-6, but without the top and bottom parts.

This glyph then ought to indicate openness, both upwards and downwards, like a pipe in the form of a piece of bamboo.