Medium cartridge and printer

A medium cartridge comprising:

• a first record medium roll that winds a record medium wound around a first axis in a manner that enables feed-out and is configured to be stored in a first storage part of a medium processor;
• a second record medium roll configured to take up and wind around a second axis at least a part of said record medium fed out from said first record medium roll, and to be stored in a second storage part of said medium processor and used;
• and
• a connecting arm that connects said first record medium roll and said second record medium roll,
• said connecting arm comprising:
• a pair of first bracket parts that sandwich said first record medium roll from one side and the other side of the first record medium roll along said first axis to rotatably hold said first record medium roll, and are provided on one side of the medium cartridge along a line that connects said first axis and said second axis;
• and
• a pair of second bracket parts that sandwich said second record medium roll from one side and the other side of the second record medium roll along said second axis to rotatably hold said second record medium roll, and are provided on the other side of the medium cartridge along said line;
• said first bracket parts comprising a substantially oval-shaped first guide part capable of entering a first lead-in groove provided in said first storage part;
• and
• said second bracket parts comprising a substantially circular-shaped second guide part capable of entering a second lead-in groove provided in said second storage part.