I did read the book, and recognized that the theme of creation (sexual and literary) seemed to tie the stories together. However, were it not for this passage in the foreward and for the first "story", I would not have thought to include it in this list of mathematical fiction.

The first "story", called Frame-tale, is actually a Mobius strip! It is a single page with the words "ONCE UPON A TIME THERE" written at one edge and "WAS A STORY THAT BEGAN" on the opposite side, with instructions for joining the ends to make a Möbius strip.

A visitor to this site, Birgit Gerdes, has written me to let me know that she believes there is a great deal of hidden mathematics in this collection of stories. In general, I shy away from such statements since I believe that you can "find" hidden math in any work of fiction (or non-fiction). However, since the author clearly had at least some mathematics in mind when writing this work, perhaps there is justification in finding mathematics in expressions such as "In sum..." which can ordinarily be used in English without any real mathematical implications.

(Also, take a look at the review of this book by mathematician Nik Weaver at his "Math in Fiction" website.)