neuroscience - Are intracortical axon branches myelinated?

I found the following pictures of axon trees:

_source

_{source (axons are red)}

but didn't find a concise answer to the following question:

Is it possibly true that the intracortical axon branches (i.e. those that don't leave the gray matter) are not myelinated? (The first picture seems to indicate that they have at least a smaller diameter, making them slower?)