def fastas_for_features_vs_masked_genomic(afasta, bfasta):
    """
    >>> fastas_for_features_vs_masked_genomic("a.fasta", "b.fasta")
    ('a.features.fasta', 'b.genomic.masked.fasta')
    """
    a = afasta.replace(".fa", ".features.fa")
    b = bfasta.replace(".fa", ".genomic.masked.fa")
    return a, b