small central hill. A prominent ridge runs up to the N. border; and on
the S.W. a rill-valley may be traced, extending S. to a bright deep
little crater W. of Cook.

CROZIER.--A conspicuous ring-plain a few miles N.N.W. of MacClure, and of
about the same size. It has a faint central hill. Neison refers to two
long straight streaks extending from Crozier towards Messier.

BELLOT.--A brilliant little ring-plain N.E. of Crozier.

COOK.--A ring-plain, about 25 miles in diameter, on the E. side of the
Mare Foecunditatis in S. lat. 17 deg., with low and (except on the S.E.)
very narrow walls. There is a small circular depression on the S. border,
and a prominent crater on the W. side of the dark interior. On the S.S.E.
is the curiously shaped enclosure Cook _d_, with very bright broad lofty
walls and a fine central mountain. On the plain W. of Cook is a
conspicuous crater-row, consisting of six or seven craters, diminishing
in size in both directions from the centre.

COLOMBO.--A fine ring-plain, about 50 miles in diameter, situated in the
highlands separating the Mare Foecunditatis and the Mare Nectaris. The
wall, rising at one place to a height of 8000 feet above the floor, is
very complicated and irregular, being traversed within by many terraces,
and almost everywhere by cross-valleys. Its shape is greatly distorted by
the large ring-plain _a_, which abuts on its N.E. flank. It loses its
individuality altogether on the S., its place being occupied by two large
depressions, and lofty mountains trending towards the S.E. In the centre
there are several distinct bright elevations.

MAGELHAENS.--The more northerly and the larger of a pair of ring-plains
between Colombo and Goclenius, with a bright and somewhat irregular
though continuous border. The dark interior includes a small central
mountain. Its companion on the S.W., Magelhaens _a_, slightly overlaps
it. This also has a central hill, and a crater on the outer slope of its
E. wall.

SANTBECH.--A very prominent ring-plain, 46 miles in diameter, on the S.E.
side of the Mare Foecunditatis, W. of Fracastorius. The continuity of its
fine lofty rampart is broken on the W., where it rises nearly 10,000 feet
above the floor, by a brilliant little crater just below the crest, and
by a narrow gap on the S. The wall on the E. towers to a height of 15,000
feet above the interior. On its broad outer slope, near the summit, there
is a fine crater, and S. of this running obliquel