as conjectured by A. von Gutschmid (Kleine Schriften, V, p. 561).

A. Rome under the Kings (Two Books).
Book I, B.C. 753-673.
Book II, B.C. 672-510.
B. Rome under a Republic (Thirty-nine Books).
a.) To the End of the Second Punic War (Fifteen Books.)
1.) To the Beginning of the Second Samnite War (Five Books):
Book III, B.C. 509.
Book IV, B.C. 508-493.
Book V, B.C. 493-449.
Book VI, B.C. 449-390.
Book VII, B.C. 390-326.
2.) To the Beginning of the Second Punic War (Five Books):
Book VIII, B.C. 326-290.
Book IX, B.C. 290-278.
Book X, B.C. 277-264.
Book XI, B.C. 264-250.
Book XII, B.C. 250-219.
3.) To the End of the Second Punic War (Five Books):
Book XIII, B.C. 219-218.
Book XIV, B.C. 218-217.
Book XV, B.C. 216-211.
Book XVI, B.C. 211-206.
Book XVII, B.C. 206-201.
b.) From the End of the Second Punic War (Twenty-four Books).
1.) To the Death of Gaius Gracchus (Eight Books):
Book XVIII, B.C. 200-195.
Book XIX, B.C. 195-183.
Book XX, B.C. 183-149.
Book XXI, B.C. 149-146.
Book XXII, B.C. 145-140.
Book XXIII, B.C. 139-133.
Book XXIV, B.C. 133-124.
Book XXV, B.C. 124-121.
2.) To the Dictatorship of Sulla (Eight Books):
Book XXVI, B.C. 120-106.
Book XXVII, B.C. 105-101.
Book XXVIII, B.C. 100-91.
Book XXIX, B.C. 90-89.
Book XXX, B.C. 88 (Happenings at Home).
Book XXXI, B.C. 88 (Events Abroad) and 87 (Happenings at Home).
Book XXXII, B.C. 87 (Events Abroad)-84.
Book XXXIII, B.C. 84-82.
3.) To the Battle of Pharsalus (Eight Books):
Book XXXIV, B.C. 81-79.
Book XXXV, B.C. 78-70.
Book XXXVI, B.C. 69-66.
Book XXXVII, B.C. 65-60.
Book XXXVIII, B.C. 59-58.
Book XXXIX, B.C. 57-54 (= a.u. 700) (Happenings at Home).
Book XL, B.C. 54 (Events Abroad)-50.
Book XLI, B.C. 49-48.
C. Rome under Political Factions and under the Monarchy (Thirty-nine Books).
a.) To the Death of Augustus (Fifteen Books).
1.) To the Triumvirate (Five Books):
Book XLII, B.C. 48-47.
Book XLIII, B.C. 46-44.
Book XLIV, B.C. 44.
Book XLV, B.C. 44-43.
Book XLVI, B.C. 43.
2.) To the Bestowal of the Imperial Title upon Augustus (Five Books):
Book XLVII, B.C. 43-42.
Book XLVIII, B.C. 42-37.
Book XLIX, B.C. 36-33.
Book L, B.C. 32-Sept. 2, B.C. 31.
Book LI, Sept. 2, B.C. 31-29 (= a.u. 725) (Events Abroad).
3.) To the Death of Augustus (Five Books):
Book LII, B.C. 29 (Happenings at Home).
Book LIII, B.C. 28-23.
Book LIV, B.C. 22-10.
Book LV, B.C. 9-A.D. 8.
Book LVI, A.D. 9-14.
b.) From the Death of Augustus (Twenty-four Books).
1.) To Vespasian (Eight Books):
Book LVII, A.D. 14-25.
Book LVIII, A.D. 26-37.
Book LIX, A.D. 37-41.
Book LX, A.D. 41-46.
Book LXI, A.D. 47 (= a.u. 800)-59.
Book LXII, A.D. 59-68.
Book LXIII, A.D. 68-69
Book LXIV, A.D. 69-70.
2.) To Commodus (Eight Books):
Book LXV, A.D. 70-79.
Book LXVI, A.D. 79-81.
Book LXVII, A.D. 81-96.
Book LXVIII, A.D. 96-117.
Book LXIX, A.D. 117-138.
Book LXX, A.D. 138-161.
Book LXXI, A.D. 161-169.
Book LXXII, A.D. 169-180.
3.) To Dio's Second Consulate (Eight Books).
Book LXXIII, A.D. 180-192.
Book LXXIV, A.D. 193.
Book LXXV, A.D. 193-197.
Book LXXVI, A.D. 197-211.
Book LXXVII, A.D. 211-217.
Book LXXVIII, A.D. 217-218.
Book LXXIX, A.D. 218-222.
Book LXXX, A.D. 222-229.