What is the type of linked list where order doesn't matter
I took a look at the book you are referencing, and it does appear that Steven Skiena made an unordered Dictionary implemented as a linked list.  It's not a terribly efficient data structure, but he was only using it to illustrate basic linked list coding techniques, so I expect he just wanted to keep things as simple as possible.

For what it's worth, a stack is a container that only allows you to add to or access from the very top item, which isn't really index based in the way we'd usually use that term.  I mention this only to highlight that Containers do not need to have index-based retrieval.