Fondness Deep

It's called a gwawdodyn (rhymes with ska-doe-din), and it hails from Wales. It is comprised of four lines (a quatrain) that follows a 9/9/10/9 syllable count. The rhyme scheme is thusly:
xxxxxxxx a
xxxxxxxx a
xxx b xxxxx b
xxxxxxxx a

There is internal rhyme present in the third line. The second version contains an internal rhyme in the fourth line while maintaining the rhyme scheme of the first version, so it may look like this:

xxxxxxxx a
xxxxxxxx a
xxxxxxxxx b
xx b xxxxx a

Thank you to Robert Lee Brewer at Writer's Digest for exposing us to this fun form. Here's an example:

Sunday morning, we found a table
topped with similar things, unable
to keep its surface level; the heaps
and heaps of memories unstable.

Fondness regrets what fondness can’t keep,
she said as we rummaged through the steep
mountains of kitschy keepsakes, heads above
the strewn clothes, heads below fondness deep.