In the field of lychnological studies, recent decades of research have offered a huge number of monographs presenting thousands of lamps. Despite this exponentially growing body of data, iconographical studies are in regress compared to other themes reaching beyond simple corpus catalogs. This paper focuses on an interesting yet unstudied Roman discus-lamp motif: the equid-driven mill. Among the representations one can easily distinguish mills driven by a donkey (mola asinaria) and by a horse (mola jumentaria). The practically exhaustive catalog of lamps adorned with those two representations is followed by a discussion of the geographical and chronological frame for each of the types.