When I saw the option "Select list" as the first option for "widget type", I thought I was being prompted to select a type of list... after about an hour of trying to figure out why there was no option to display the field as a dropdown listbox, I realized of course that this not a prompt for me to select a type of list, but that "Select list" was itself an option.

This indicates a minor usability problem, which could be easily resolved by changing the label to "Dropdown listbox", or "selection list", etc.