northwest from the Lacus Phoenicis, is the Pyriphlegethon. In this plate the Sea of the Sirens is well on, its beak being almost on the central meridian. From its north coast strike down a great many canals, all going as far as the Eumenides and some continuing past it. The first one from the Beak of the Sirens is the Sirenius. It crosses the Eumenides at the first of its large spots after leaving the Phoenix Lake, the Lucus Arsine. To the next spot, known as the Nodus Gordii, the Gorgon comes down from time centre of the coast-line, meeting the Gigas, which itself debouches, at the west end of the sea, into what is called the Sinus Titanum, or Gulf of the Titans.
In Plate VIII. the Sinus Titanum has come round into view. Owing to its conspicuousness at certain seasons, it is one of time most import ant features on the planet to us, and seems to be to the planet itself, as some seven canals radiate from it. These are the Gigas, previously described, and to the right, in the order here enumerated, the Steropes, the Brontes, the Titan,—the one straight down the disk,—the Arges, the Gyes, and the Tartarus; the last traveling to the Trivium Charontis invisible in this plate. Of the separate existence of the Arges and the Gyes I am not quite certain. These great canals show like the sticks of a fan, with the Sinus itself for pivot.