All codex means is that it has an ordered index system.
A codex refers to the specific type of binding. Scrolls are not bound in the same fashion as a codex.
“a quire of manuscript pages held together by stitching: the earliest form of book, replacing the scrolls and wax tablets of earlier times.”
http://dictionary.reference.com/browse/codices
Calling something a ‘codex of scrolls’ is a misnomer. Codexes are an upgrade from scrolls.