We will not say whether the old masters painted this cirrus or not.
There must be text-books on how to tell the cumuli from the cirrus.
The third cirrus is about one third longer than the second cirrus.
In the sixth cirrus there are on each segment four pairs of spines.
The rami of the first cirrus are a little unequal in length.
This is the cirro-stratus, and is a ...