def species_list(what_list):
    """
    provide default lists of elements to plot.

    what_list : string
        String name of species lists provided.

        If what_list is "CNONe", then C, N, O and some other light
        elements.

        If what_list is "s-process", then s-process indicators.

    """
    if what_list is 'CNONe':
        list_to_print = ['H-1', 'He-4', 'C-12', 'N-14', 'O-16', 'Ne-20']
    elif what_list is 'sprocess':
        list_to_print = ['Fe-56', 'Ge-70', 'Zn-70', 'Se-76', 'Kr-80',
            'Kr-82', 'Kr-86', 'Sr-88', 'Ba-138', 'Pb-208']
    elif what_list is 'burn_stages':
        list_to_print = ['H-1', 'He-4', 'C-12', 'O-16', 'Ne-20', 'Si-28']
    elif what_list is 'list_marco_1':
        list_to_print = ['C-12', 'O-16', 'Ne-20', 'Ne-22', 'Na-23', 'Fe-54',
            'Fe-56', 'Zn-70', 'Ge-70', 'Se-76', 'Kr-80', 'Kr-82', 'Sr-88',
            'Y-89', 'Zr-96', 'Te-124', 'Xe-130', 'Xe-134', 'Ba-138']
    return list_to_print
