r formation, about 50 miles in diameter, on the S.W. of
Petavius, with which it is connected by extensions of the W. and E. walls
of the latter. Its rampart, some 7000 feet above the floor, is broken by
depressions on the W.; and on the S. is bounded by a smaller ring-plain
with still loftier walls. Schmidt shows a large crater and three smaller
ones on the W. side of the floor.

MARINUS.--A ring-plain on the N.E. side of the Mare Australe, between
Furnerius and the limb.

FURNERIUS.--The fourth and most southerly component of the great
meridional chain of walled-plains, commencing on the N. with Langrenus: a
fine but irregular enclosure, about 80 miles in extreme length and much
more in breadth. Its rampart is very lofty, and tolerably continuous on
the N. and W., but on the other sides is interrupted by small craters and
depressions. At peaks on the E. it attains a height of more than 11,000
feet above the interior, and there are other peaks rising nearly as high.
There is a ring-plain (Furnerius B) with a central hill, on the E. side
of the floor, and numerous craters and crater-pits in other parts of it.
On the N.W. side of B there is a short cleft, on the W., a well-marked
crater-row, and on the E. a long rill-valley. The very brilliant crater
(Furnerius A) on the N.E. _glacis_ is the origin of two fine light
streaks, one extending S. for more than 100 miles, and the other in the
opposite direction for a great distance.

FRAUNHOFER.--A ring-plain, S. of Furnerius, about 30 miles in diameter,
with a regular border rising about 5000 feet above the floor. A smaller
ring-plain abuts on the N.E. side of it, which has slightly disturbed its
wall.

OKEN.--A large enclosure in S. lat. 43 deg. with broken irregular walls.
It is too near the limb for observation.

VEGA.--Schmidt represents this peculiar formation, situated S.E. of Oken,
as having a regular curved unbroken rampart on the E., while the opposite
border is occupied by four large partially overlapping ring-plains, two
of which contain small craters. The floor is devoid of detail.

PONTECOULANT.--A great irregular walled plain, about 100 miles in length,
near the S.W. limb, with a border rising in places to a height of 6000
feet above the floor.

HANNO.--A smaller and more regular enclosure, adjoining Pontecoulant on
the N.W., and still nearer the limb.

WEST LONGITUDE 60 deg. TO 40 deg.

MESSIER.--The more westerly of a remarkable pair of bright cr