Umbilicus Romae : a monument erected not earlier than the time of
Severus (AJA 1909, 186) on the north end of the hemicycle of the Rostra
(q.v.), and mentioned only in later literature (Not. Reg. VIII; Eins.
i. 5 1 7-71 8. 8 ; DAP 2. ix. 389). It is now a cylindrical brick-faced
core, rising in three stages, with a diameter of 4.60 metres at the bottom
and 3 at the top, but originally it was covered with marble. It represented
the central point of city and empire, probably in imitation of the
όμφαλός in Delphi and other Greek cities, and may have corresponded
architecturally to the Milliarium Aureum (q.v.) at the south end of
the hemicycle (Jord. i. 2. 245 ; HC 80 ; Thedenat 134, 233).
Urbis Fanum : see Venus et Roma.
Urbis Fanum : a temple constructed by Maxentius, and consecrated to
Constantine (Aur. Victor. 40. 26 : cuncta opera quae magnifice con-
struxerat urbis fanum atque basilicam Flavii meritis patres sacravere).
It has recently been identified with the round structure generally called
the Templum divi Romuli, which has an entrance on the Sacra via, the
bronze doors of which are still preserved. There is a fagade of four
columns, behind which on each side is a niche. The construction shows
a clever use of an awkward triangular site (RA 215-217). See Pax,
templum; and cf. BCr 1913, 143-165; YW 1913, 21, 22; JRS 1919,
177-179; DR 376, 377 ; RAP iii. 94-98 ; AJA 1927, 1-18 ; HFP 48, 49.
Ad Ursum Pileatum : the name of a cemetery on the Via Portuensis
where the bodies of SS. Abdon and Sennen were buried (Chron. Min. i. 71 ;
LP lxxxii. 5). Pope Leo II (682-684) transferred the bodies of SS.
Faustinus, Simplicius, and Beatrix from the cemetery of Generosa (also
on the Via Portuensis) to a church of S. Paul close to S. Bibiana, not
far from the Porta Tiburtina, which he founded (LPD i. 361, n. 9 ; HCh
415). Here, in the sixteenth century, Bosio (Roma Sotterranea, lib. iii.
c. 66, p. 585) read an inscription, which began as follows, ‘ anno domini
. . . mense Octobris dedicatione(m) huius eccl(esia)e s(an)c(t)or(um)
martir(um) Simplicii Faustini et Beatricis ad cimeterium Ursi Pileati
iuxta forma(m) Claudii an(te) po(r)ta(m) Taurinam quam primus [τΰ]
Leo papa maxima devotione . . . fecit.’ This shows that the name had
wrongly been transferred to this district in the Middle Ages and by the
topographers of the sixteenth century (cf. CIL vi. 3403*). For a statue