<p>In a magnetic tape cartridge comprising a magnetic tape wound around a single reel and a substantially rectangular cartridge casing which is formed by fastening upper and lower casing halves by a fastener means and in which the reel is housed for rotation, a tape draw-out opening is provided in a corner of the cartridge casing, and a non-contact memory element is provided in at least one of the other three corner portions in the lower casing half. <IMAGE></p>
