A Dictionary of Christian Antiquities: Being a Continuation of the “Dictionary of the Bible”, edited by William Smith and Samuel Cheetham, vol. 2 (K–Z), in the article “MARCUS (1), the Evangelist” (the entry is signed [C. H.] in the margin).

MARCUS (1), the Evangelist, was very generally commemorated, and his name occurs in the Greek, Latin, and Coptic fasti, but not always on the same day. Sept. 23 is assigned to his natalis at Alexandria in Hieron. Mart., but one MS. omits natalis (Acta SS. infra). The Cal. Byzant. commemorates Mark, “the apostle,” on Jan. 11, and the Bollandists identify him with the evangelist, who is called in the same calendar, under Ap. 25, “evangelist and apostle,” and in Basil. Menol., under the same day, “apostle and evangelist.” April 25 is the day more usually assigned to him (Usuard. Mart.; Bed. Mart.; Vet. Rom. Mart.; Daniel. Cod. Liturg. iv. 238; Boll. Acta SS. Apr. iii. …)