EIMMART.—­A conspicuous ring-plain with bright walls on the N.W. margin of the Mare Crisium.  The E. border attains a height of 10,000 feet above the interior, which, according to Schmidt, has a small central mountain.  There is a rill-like valley on the E. of the formation.

ORIANI.—­An irregular object, 32 miles in diameter, somewhat difficult to identify, N.W. of the last.  There is a conspicuous crater on the N. of it, with which it is connected by a prominent ridge.

PLUTARCH.—­A fine ring-plain W. of Oriani, with regular walls, and, according to Neison, with two central mountains, only one of which I have seen.  Both this formation and the last are beautifully shown in a photograph taken August 19, 1891, at the Lick Observatory, when the moon’s age was 15 d. 10 hrs.

SENECA.—­Rather smaller than Plutarch.  Too near the limb for satisfactory observation.  Schmidt shows two considerable mountains in the interior.  The position of this object in Schmidt’s chart is not accordant with its place in Beer and Madler’s map, nor in that of Neison.

HAHN.—­A ring-plain, 46 miles in diameter, with a fine central mountain and lofty peaks on the border, which is not continuous on the S. There is a large and prominent crater on the E.

BEROSUS.—­A somewhat smaller object of a similar type, N. of Hahn, but with a loftier wall.  There is a want of continuity also in the border, the eastern and western sections of which, instead of joining, extend for some distance towards the S., forming a narrow gorge or valley.  Outside the S.E. wall there is a small crater, and some irregular depressions on the E. The minute central mountain is only seen with difficulty under a low evening sun.  The bright region between Hahn and Berosus and the western flank of Cleomedes is an extensive plain, devoid of prominent detail, and which, according to Neison, includes an area of 40,000 square miles.

GAUSS.—­A large, and nearly circular walled-plain, 111 miles in diameter, situated close to the N.W. limb, and consequently always foreshortened into a more or less elongated ellipse.  But for this it would be one of the grandest objects in the first quadrant.  Under the designation of “Mercurius Falsus” it received great attention from Schroter, who gives several representations of it in his Selenotopographische Fragmente, which, though drawn in his usual conventional style, convey a juster idea of its salient features than many subsequent drawings made under far better optical conditions.  The border, especially on the W., is very complex, and is discontinuous on the S., where it is intersected by more than one pass, and is prolonged far beyond the apparent limits of the formation.  The most noteworthy feature is the magnificent mountain chain which traverses the floor from N. to S. It is interesting to watch the progress of sunset thereon, and see peak after peak disappear, till only the great central boss and a