How Ythrians Sleep and Details Of Gray/Avalon

"The Problem of Pain," here.

I asked here whether we are told how Ythrians sleep. I had already answered the question in How Aliens Sleep. However, to go through it again -

On board a ship in a storm:

"The Ythrian female locked hands and wing-claws around the net-covered framework wherein she had slept..." (p. 34)

On land:

"The Ythrians were quickly asleep, squatted on their locked wing joints..." (p. 40)

The story introduces important Avalonian details:

the largest continent (Corona);
a gulf (Falkayn Bay);
an archipelago (Oronesia);
hell shrubs;
surgeon trees;
atlantis weed;
the feasibility of joint colonization.