at the foot of the Wall of Rome in several places, they were distinctly visible in 1870, when these photographs were taken; but have been almost obliterated since in the _restoration_ (?) of the wall by the municipal architect. One is near the Porta Metronia (983), and another at the Porta Latina (985). Remains of other _piscinæ_ are visible near the Amphitheatrum Castrense, on the rock at the foot of the wall (868, 969, 970); at this point one branch of it seems to have been brought into Rome along the line of the Via Appia Nova, which runs near the spot, and entered Rome just beyond, by the Porta Asinaria. It can also be seen at the foot of a wall by the side of the Via Labicana, near the Porta Maggiore, and readily distinguished by the usual reticulated work (1337). One branch enters Rome at the foot of the Marcian Arcade, close to the Porta Maggiore (59), and the _specus_ was visible at that gate, until it was concealed by a brick wall by the modern builders. It passes through the City Wall there, and is visible on the other side in the inner road, in the wall of the garden still under the level of the Marcian Arcade (1876). Here it forked off, one branch went to the left, along the line of the wall of the garden, to a great reservoir for it at an angle close to the junction of two roads, one called the Via Labicana the other the Via di Porta Maggiore, coming from the church of S. Maria Maggiore. At this spot there is a very large and fine reservoir in several chambers at a considerable depth, corresponding to the level of the Anio Vetus; 538 is a view of it, and 700* is a section of it. From this great reservoir two small _specus_ in this part appear to have gone into the _specus_ of the Appia in the Cœlian, under the Arches of Nero, and are visible going into the bank on which this fine arcade stands (854). Another important branch turns to the north upon the high bank of the Kings, on which the Wall of Aurelian was afterwards built. There are remains of _castella_ for it near the Porta S. Lorenzo (869), and further to the south near the Porta Nomentana (871), after passing the Prætorian Camp. It had previously gone under the Porta Chiusa, which was shewn in the excavation of 1868, and in the photograph 1057. The _specus_ runs under the wall of the Camp all round. It is still visible on the north side, faced with the reticulated work under the fine brickwork of Tiberius (870). There was an opening into it at the north-east corner of the camp, into which a dog or a boy might be sent (981, 982), until it was closed in the recent _restoration_. Remains of it may still be seen at the foot of the wall in several places by experienced eyes. The general plan of this aqueduct is shewn in Nos. 1970*, 1971*, 1976*, 1977*, and 1967*. III. MARCIA, MADE IN THE YEAR OF ROME, 608, B.C. 145.[223]