  Recently, Yamazaki et al. provided an algorithm that enumerates all
non-isomorphic interval graphs on $n$ vertices with an $O(n^4)$ time delay. In
this paper, we improve their algorithm and achieve $O(n^3 \log n)$ time delay.
We also extend the catalog of these graphs providing a list of all
non-isomorphic interval graphs for all $n$ up to $15$.
