W. HERSCHEL.--A vast enclosed plain, about 90 miles across, bounded
on the W. by a mountain range, which here defines the E. side of the Mare
Frigoris, on the S. by massive mountains, and on the other sides by a
lofty but much broken wall, intersected by many passes. Within is a large
ring-plain, nearly central, and a large number of little craters and
crater-pits. The floor is traversed longitudinally by many low ridges,
lying very close together, which at sunrise resemble fine grooves or
scratches of irregular width and depth.

HORREBOW.--A ring-plain of remarkable shape, resembling the analemma
figure, standing at the S. end of the mountain range bounding J.F.W.
Herschel on the W. Schmidt shows a crater on the W. wall, near the
constriction on this side, and a second at the foot of the slope of the
E. wall.

PHILOLAUS.--A ring-plain 46 miles in diameter, on the N.E. of Fontinelle.
Its bright walls rise on the W. to a height of nearly 12,000 feet above
the floor (on which there is a conspicuous central mountain), and exhibit
many prominent terraces. Philolaus is partially encircled, at no great
distance, by a curved ridge, on which will be found a number of small
craters.

ANAXIMINES.--A much foreshortened ring-plain, about 66 miles in diameter,
on the E. of Philolaus. One peak on the E. is nearly 8000 feet in height.
Schmidt shows four craters on the W. side of the floor, and a fifth on
the S.E. side. There is a bright streak in the interior, which extends
southwards for some distance across the Mare Frigoris.

EAST LONGITUDE 40 deg. TO 60 deg.

REINER.--A regular ring-plain, 21 miles in diameter, in the Mare
Procellarum, S.S.E. of Marius, with a very lofty border terraced without
and within, and a minute but conspicuous mountain standing at the N. end
of a ridge which traverses the uniformly dark floor in a meridional
direction. A long ridge extends some way towards the S. from the foot of
the S. wall, and at some distance in the same direction lie six ill-
defined white spots of doubtful nature. On the E.N.E. there is a large
white marking, resembling a "Jew's harp" in shape, and farther on,
towards the E., a number of very remarkable ridges. On the W. will be
found many bright little craterlets. A ray from Kepler extends almost up
to the W. wall of Reiner.

MARIUS.--A very noteworthy ring-plain, 27 miles in diameter, in the
Oceanus Procellarum, E.N.E. of Kepler, with a bright border rising about
4000 f