CARDANUS.—­A fine regular ring-plain, about 32 miles in diameter, near the limb N. of Olbers.  Its bright walls, rising about 4000 feet above the light grey floor, are clearly terraced, and exhibit, especially on the S.E., several spurs and buttresses.  There is a fine valley on the outer W. slope, a large bright crater on the Mare just beyond its foot, and a conspicuous mountain in the same position farther north.  I have not succeeded in seeing the faint central hill nor the crater N. of it shown by Schmidt, but there is a brilliant white circular spot on the floor at the inner foot of the N.E. wall which he does not show.

KRAFFT.—­A very similar object on the N., of about the same dimensions; with a central peak, and a large crater on the dark floor abutting on the S.W. wall, and another of about half the size on the outer side of the W. border.  From this crater a very remarkable cleft runs to the N. wall of Cardanus:  it is bordered on either side by a bright bank, and cuts through the N.W. border of the latter formation.  It is best seen when the E. wall of Cardanus is on the morning terminator.

VASCO DE GAMA.—­A bright enclosure, 51 miles in diameter, with a small central mountain.  It is associated on the N. with a number of enclosed areas of a similar class, all too near the limb to be well seen.

SELEUCUS.—­A considerable ring-plain, 32 miles in diameter, with lofty terraced walls, rising 10,000 feet above a dark floor which includes an inconspicuous central hill.  This formation stands on a ridge extending from near Briggs to the W. side of Cardanus.

OTTO STRUVE.—­An enormous enclosure, bounded on the E. by the Hercynian Mountains, and on the W. by a mountain chain of considerable altitude, surmounted by three or more bright little rings.  On the W. side of the uneven-toned interior, which, according to Madler, includes an area of more than 26,000 square miles, stand four craters, several little hills, and light spots.  On the W. is the much more regular and almost as large formation, Otto Struve A, the W. border of Otto Struve forming its E. wall.  This enclosure is bounded elsewhere by a very low, broken, and attenuated barrier.  At sunrise the E. and W. walls, with the mountain mass at the N. end, which they join, resemble a pair of partially-opened calipers.  There is one conspicuous little crater on the W. side of the floor; and, at or near full moon, four or five white spots, nearly central, are prominently visible.

BRIGGS.—­This bright regular ring-plain, 33 miles in diameter, is situated a short distance N. of Otto Struve A. A long ridge traverses the interior from N. to S. On the E. is another large enclosure, communicating with Otto Struve on the S., and really forming a N. extension of this formation.  It has a large and very deep crater, 12 miles in diameter, on its W. border.

LICHTENBERG.—­A conspicuous little ring-plain, about 12 miles in diameter, in an isolated position on the Mare, some distance N. of Briggs.  It was here that Madler records having occasionally noticed a pale reddish tint, which, though often searched for, has not been subsequently seen.