Illustration from "Picture Natural History" - No 24 - The Otter  <a class="external free" href="https://en.wikipedia.org/wiki/Otter">https://en.wikipedia.org/wiki/Otter</a>
Mary E. C. Boutell
Picture Natural History <a rel="nofollow" class="external autonumber" href="https://archive.org/details/PictureNaturalHistory">[1]</a>