And then there is something wrong in explaining the variants of GD16 and GD24 with only one rim as being due to a shield (GD16) or eggs (GD24). I believe that we see a water hole when there are two rims. And I believe that there are two water holes, one to get into the underworld and another to get out from there, which explains GD24 with two rims as the henua of the underworld.

This also explans why there is a GD24-glyph with two rims in Saturday. Another idea about Saturday wich suddenly strikes me: the special kind of 'henua'

might be another type of picture of the henua of the underworld. In darkness you cannot see clearly and the straight lines of the rays from the sun cannot give you any help. There just cannot be straight lines in a glyph attempting to show the underworld henua.

The fact that holes in GD16 and GD24 are pictured in the same form as the sun (without flames) is like a pun: You can see a hole or you can see the sun. And if you chose to see the sun and this grows into a habit, then you might later write the sun 'as it should be', that is with only one rim. Two rims might mean a double-month or something similar (remember the signs on Pachamama), at least when there are no flames in the glyph.

A henua for the underworld with the short ends defined not by straight lines but by the form of the sun (or perhaps rather of the moon?) is logical: There is no exact border in the processes of life and death, not even when it is the sun who is 'being born' or 'dying'.