The Solis Lacus is a great oval patch, measuring along its longest diameter five hundred and forty miles. With small telescopic power or in poor air it appears of uniform tint through out, but under better visual conditions dark spots appear in it, and bright causeways, which divide it into five portions. Its longitudinal dividing line is prolonged into the Nectar, the short canal connecting it with the dark regions to the east. The Nectar thus appears double. Nor does the causeway stop here. It continues on between double dark lines until it reaches the long rectangular area spoken of before as a sort of continuation of the Ganges.
But a second feature of this region is no less note worthy. Surrounding the Solis Lacus is a perfect cordon of canals and spots, the chief of which are the Tithonius Lacus, nearly due north, and the Lacus Phoenicis, or Phoenix Lake, north- west. The spots are strung like beads upon the loop of the Agathodaemon and the Daemon. From the northeast end of this string of spots runs the Chrysorrhoas to the Lacus Lunae on the fifty-eighth meridian. Below it is the Labeatis Lacus, from which the Gigas starts west, to be lost in the limb-light.
In the next plate (Plate VI.), the Solis Lacus is central, the Lacus Phoenicis somewhat to the right of the centre; and southwest of the Lacus Phoenicis is the Beak of the Sirens, the eastern
