eat depressions on the N. side of it.

EAST LONGITUDE 20 deg. TO 40 deg.

LANDSBERG.--A ring-plain, about 28 miles in diameter, situated in Mare
Nubium, S.E. of Reinhold, which in many respects it resembles. Its
regular massive border is everywhere continuous. Only a solitary crater
breaks the uniformity of its crest, that rises on the W. to nearly 10,000
feet, and on the E. to about 7000 feet above the floor, which is
depressed about 7000 feet below the surrounding surface. The inner slopes
exhibit some fine terraces, and on the broad W. _glacis_ is a curious
winding valley, which runs up the slope from the S.W. side to the crater
just mentioned, then, bending downwards, joins the plain at the foot of
the N. wall. Neither this nor the crater is shown in the maps. The large
compound central peak is apparently the sole object in the interior. At 8
h. 25 m. on January 23, 1888, when observing the progress of sunrise on
this formation with a 8 1/2 inch Calver-reflector charged with different
eyepieces, I noticed, when about three-fourths of the floor was in
shadow, that the illuminated portion of it was of a dark chocolate hue,
strongly contrasting with the grey tone of the surrounding district. This
appearance lasted till the interior was more than half illuminated,
gradually becoming less pronounced as the sun rose higher on the ring. E.
and S.E. of Landsberg is a number of ring-plains and craters well worthy
of careful examination. Five of the largest are surrounded by a
glistening halo, and one (that nearest to the formation) and another (the
largest of the group) have each a minute crater on their N. wall.

EUCLIDES.--One of the most brilliant objects on the moon; a crater 7
miles in diameter, standing on a large bright area in the Mare
Procellarum, E. of the Riphaean Mountains. Its E. rim rises nearly 2000
feet above the bright depressed floor; on the W. there is a bright little
unrecorded crater.

WICHMANN.--This bright crater, about 5 miles in diameter, stands on a
light area in Oceanus Procellarum, N.N.W. of Letronne and nearly due E.
of Euclides. Some distance on the N.E. are the relics of what appears
once to have been a large enclosure, represented now by a few isolated
mountains.

HERIGONIUS.--A ring-plain, about 7 miles in diameter, in the Mare
Procellarum, N.W. of Gassendi. There is a small crater a few miles S.E.
of it, among the bright little mountains which flank this formation.
Herigonius has a