OK, I see what's happening. I allow visitors access to the directory listing of many of my folders, so they can browse them, directly, by not including an index.htm file in those folders. Sitemap is adding
Index of /path/
lines for each of these open folders. That must be the reason the links in these lines look like Apache folder queries. I'm assuming I could stop this behavior by adding index.htm files to each of these folders. I can do it for the /Census/ folders without having a significant impact on visitors (there is a CensusHub file allowing them to locate files), but I don't want to do that for the /FGS/ (family group sheet folder), which is the largest section of my site (11,000 of the 15,000 pages), even though there is an index file to these folders. There are distinct advantages to being able to browse the files there.
Is there some way we can get the sitemap generator to stop adding links to the directory listings of open folders?