One of the pictures in William Saville-Kent’s piece “A manual of the Infusoria : including a description of all known flagellate, ciliate, and tentaculiferous protozoa, British and foreign, and an account of the organization and the affinities of the sponges” (London, D. Bogue, 1880-1882) features Monosiga gracilis (synonyms Codosiga gracilis, Hartaetosiga (Codosiga) gracilis (Kent) Carr, Richter and Nitsche), which belongs to a ubiquitous group of aquatic bacterivorous filter feeders. The text accompanying the picture reads: “A collared monad – Monosiga gracilis, S.K. Artificially fed with, carmine. The Arrows denote the direction, of the current, induced by the rotatory motion of the flagellum, and the course taken, by the food particles on striking against and adhering to the extended collar. cl. colar fl. flagellum fg. food globules. n. Endoplast or nucleus.” Image by Biodiversity Heritage Library, sponsored by Harvard University, Museum of Comparative Zoology, Ernst Mayr Library and retrieved from Flickr; image modified by MIC. The cover is published under the Creative Commons Attribution (CC BY) license.