ses to the height of 10,000 feet. There is a long ridge on
the floor, running from E. to W.

GIOJA.--A ring-plain about 26 miles in diameter, near the north pole.

EAST LONGITUDE 20 deg. TO 40 deg.

REINHOLD.--A prominent ring-plain, 31 miles in diameter, with a lofty
border, rising at a peak on the W. to more than 9000 feet above the
floor. Its shape on the W. is clearly polygonal, the wall consisting of
three rectilineal sections, and on the E. it is made up of two straight
sections connected by a curved section. The inner slope includes a
remarkably distinct and regular terrace, the E. portion of which is well
seen when the interior is about half illuminated by the rising sun. At
this phase also the great extent of the _glacis_ on the S.W., and the
deep wide gullies traversing it on the E. are observed to the best
advantage. The central mountain, though of considerable size, is not
prominent. Close to Reinhold on the N.W. stands a noteworthy little
formation with a low and partially lineal wall, exhibiting a gap on the
north. There is a distinct crater on the S. side of its floor.

GAY-LUSSAC.--A very interesting ring-plain, 15 miles in diameter,
situated in the midst of the Carpathian Highlands N. of Copernicus, with
a smaller but brighter and deeper formation (Gay-Lussac A) on the S.W. of
it, and a conspicuous little crater, not more than 2 or 3 miles in
diameter, between the two. The interior of Gay-Lussac is traversed by two
coarse clefts, lying nearly in a meridional direction. The more easterly
runs from the foot of the S. wall, near the little crater just mentioned,
across the floor to the low N. border, which it apparently cuts through,
and extends for some distance beyond, terminating in a great oval
expansion. The other, which is not shown in the maps, is closely parallel
to it, and can be traced up to the N. border, but not farther. Schmidt
represents the first as a crater-row, which it probably is, as it varies
considerably in width. From the S.E. side of the formation extends a long
cleft, terminating at the end of a prominent spur from the S. side of the
Carpathians. There are also two remarkable rill-like valleys, commencing
on the N. of Gay-Lussac A, which curve round the W. side of Gay-Lussac.

HORTENSIUS.--This brilliant crater, about 10 miles in diameter, is
remarkable for its depth, and as being a ray-centre surrounded by a
nimbus of light. It has a central mountain, and Schmidt shows a min