Albert Marth discovered NGC 4538 = m 242 on 22 Mar 1865 and noted "eF, vS, nearly R." His position matches CGCG 042-161 = PGC 41850.
400/500mm - 17.5" (3/24/90): very faint, small, elongated 5:2 WSW-ENE, low even surface brightness. NGC 4544 lies 22' SE.
Notes by Steve Gottlieb