Catharine Johnston (née Charles; 1794–1871) was an English botanical illustrator who had a species of marine animal named in her honour.
[3] On 23 November 1819, she married George Johnston,[4] a naturalist, and moved to Berwick-on-Tweed, where the couple resided permanently.
[5] She assisted her husband in his natural history investigations and illustrated his publications with scientific drawings.
[8] In 1853 Philip Henry Gosse named the marine species Tomopteris (Johnstonella) catharina in her honor stating: The crystalline Johnstonella: I have pleasure of announcing a new animal of much elegance, which I believe to be of a hitherto unrecognised form.
I venture respectfully to appropriate to this marine animal, the surname and christian name of Mrs. Catharine Johnston, as a personal tribute of gratitude for the great aid which I have derived from her engravings in the study of zoophytology.