Close to the Janus Quadrifrons stands a stone ornamental doorway now partly built into the wall of the church of S. Giorgio in Velabro. It is constructed of brickwork with marble facings, and consists of two square piers decorated with pilasters of the Composite or Roman order at the corners and surmounted by a horizontal entablature of rich carved work. There is no trace of an attica above. The inscription, still well preserved, shows that it was erected by the money-changers or bankers, and other merchants of the Forum Boarium, in honour of Septimius Severus, his wife Julia, and his son Antoninus (Caracalla). As in the case of the Arch of Septimius in the Forum, so here the words III. PP. PROCOS. FORTISSIMO FELICISSIMOQUE PRINCIPI and PARTHICI MAXIMI BRITANNICI MAXIMI were inserted by Caracalla in place of the name and titles of his murdered brother Geta. Not only in the inscriptions of the time of Septimius Severus, but even in the reliefs we everywhere find Geta’s figure erased. On the shafts of the pilasters are representations of military ensigns, which bear upon their circular tablets and above the eagles likenesses in relief of two Cæsars, Severus and Caracalla. The third likeness, that of Geta, has been erased in every instance. In each of the spaces between the pilasters are four panels with sculptures in relief. The lowest of these represents the merchants of the Forum Boarium bringing cattle as victims to the altar. The compartment above these exhibits various instruments used in sacrifice, similar to those found upon the Temple of Vespasian. Upon the larger central panel are the figures of the imperial family engaged in sacrificing, and it can easily be seen that from some of these the figure of Geta has been carefully chiselled away. In one of these large panels is the figure of a barbarian captive with the Phrygian cap so common upon the sculptures of the triumphal arches. The upper compartments contain festooned ornamental work and a few figures of men. The front of the architrave and frieze is almost entirely occupied by the inscriptions, and is not highly ornamented, but the cornice, which is divided into seven ledges, is overladen with various decorative patterns without purity of design or excellence of execution. The date of the erection of this monument is stated in the inscription to be the twelfth year of the tribunitia potestas of Severus and the seventh of Caracalla, which corresponds to the year A.D. 204. Reber thinks it possible that the merchants of the Forum Boarium intended it as a testimonial of gratitude to Severus for having built the neighbouring Janus Quadrifrons to ornament their quarter of the city. [Sidenote: Cloaca Maxima.]