The Roman Canon (Eucharistic prayer in the Traditional Latin Mass) has two lists of Saints, one before the Consecration and one after.
The first list begins with the Blessed Virgin Mary who, being the Queen of All Angels and Saints, stands alone. Next is St. Joseph who, being the Forster Father of Christ, also stands alone. Next are listed the original 11 Apostles with St. Paul to make 12, and then 12 early martyrs. These 24 martyrs (the Apostle John survived his by a miracle) represent the 24 Elders in the Apocalypse (4:4). These 24 elders are interpreted as symbolizing all the fathers and the more illustrious holy men of both Testaments.
The list after the Consecration begins with St. John the Baptist, who stands alone as he is the greatest of the Prophets. Then there are the names of 7 male saints and of 7 female saints. Since 7 is the number of completion, these two groups of 7 saints symbolize the complete number of all male and female saints. As all the saints are implicitly included in these lists, no other names need to be added by the Priest.