If what you mean by denomination is any ecclesial body that retains a jurisdiction, or a semi-autonomy, then you will have to admit that even the Catholic Church is not "one". According to David A. Barretts World Christian Encyclopedia: A Comparative Survey of Churches and Religions in the Modern World A.D. 19002000 (ed. David A. Barrett; New York: Oxford University Press, 1982), there are seven major ecclesiastical blocs under which these 22,190 distinct denominations fall (Barrett, 14-15): (1) Roman Catholicism, which accounts for 223 denominations; (2) Protestant, which accounts for 8,196 denominations; (3) Orthodox, which accounts for 580 denominations; (4) Non-White Indigenous, which accounts for 10,956 denominations; (5) Anglican, which accounts for 240 denominations; (6) Marginal Protestant, which includes Jehovahs Witnesses, Mormons, New Age groups, and all cults (Barrett, 14), and which accounts for 1,490 denominations; and (7) Catholic (Non-Roman), which accounts for 504 denominations.
The Orthodox have nineteen traditions, while the Roman Catholic has sixteen of which are including Latin-rite local, Latin-rite catholic, Latin/Eastern-rite local, Latin/Eastern-rite catholic, Syro-Malabarese, Ukrainian, Romanian, Maronite, Melkite, Chaldean, Ruthenian, Hungarian, plural Oriental rites, Syro-Malankarese, Slovak, and Coptic.
There are four major groups within Roman Catholicism: (1) Catholic Pentecostals (Roman Catholics involved in the organized Catholic Charismatic Renewal); (2) Christo-Pagans (Latin American Roman Catholics who combine folk-Catholicism with traditional Amerindian paganism); (3) Evangelical Catholics (Roman Catholics who also regard themselves as Evangelicals); and (4) Spiritist Catholics (Roman Catholics who are active in organized high or low spiritism, including syncretistic spirit-possession cults). And of course, we all know that this list can be supplemented by distinctions between moderate Roman Catholics (represented by almost all Roman Catholic scholars), Conservative Roman Catholics (represented by Scott Hahn and most Roman Catholic apologists), Traditionalist Roman Catholics (represented by apologist Gerry Matatics), and Sedevacantist Roman Catholics (those who believe the chair of Peter is currently vacant).
So, I know, Annalex, you probably would love if everyone saw your religion as unified, but in reality, there are divisions and various beliefs among the people who identify as Catholic. The unity that Christ prayed for IS an answered prayer because those who trust in him as their savior are all members of the same spiritual body, the outward labels or signs on doors may be different but there is still unity on the major tenets that make up the Christian faith. Your organization does NOT have dominion over the name Christian. It is Jesus' body and he says who belongs within it.
The distinctions you point out are in part imaginary and in part exist but such as they are, they reflect the breadth of the spiritual life of the Catholic people. In fact, the method your authrour chose is not the best, more natural way to further subdivide Catholics would be by religious order, such as Bendedictine, Franciscan, Jesuit, etc. which really reflect different spiritualities.
But nether of these are denominations; we all worship in the same Church and beleive in the same dogmas. The more important division that exists in the Church is that with the Orthodox, who are a collection of local Churches not in union with Rome, and the small group you mention, Sedevacantists. Those sometime are counted as Catholics with imperfections and sometimes are not. At least for the purposes of the exposition of the Catholic doctrine they are all Catholic. I for example, would use Orthodox apologetical material alongside Western Catholic.
While these distinctions are as old as the Church itself, "denomination" is the invention of Protestantism. The difference is not in the words, of course, but in the essence. The idea that the Bible alone is the source of doctrine has lead to apperance of leaders, like Calvin, Knox, or Wesley who each hold only their doctrine the full truth. In contrast, no group inside Catholicism rejects in any part the theological doctrines of the other and they do not have separate leadership structures.