The border is much broken by gaps and intersected by passes, especially E. and S., where there are several valleys connecting the interior with that of Alphonsus.  The loftiest portion of the wall, which includes many crateriform depressions, is on the W., where one peak rises to nearly 9000 feet.  Another on the N.E. is about 6000 feet above the interior.  On the N.W. is a remarkable crater-row, called, from its discoverer, “Webb’s furrow,” running from a point a little N. of a depression on the border to a larger crateriform depression on the S. of Hipparchus K. Birt terms it “a very fugitive and delicate lunar feature.”  As regards the vast superficies enclosed by this irregular border, it is chiefly remarkable for the number of large saucer-shaped hollows which are revealed on its surface under a low sun.  They are mostly found on the eastern quarter of the floor.  Some of them appear to have very slight rims, and in two or three instances small craters may be detected within them.  Owing to their shallowness, they are very evanescent, and can only be glimpsed for an hour or so about sunrise or sunset.  The large bright crater A, about 4 miles in diameter on the N.W. side of the interior, is by far the most conspicuous object upon it.  Adjoining it on the N. is a large ring with a low border, and N. of this again is another, extending to the wall.  Mr. Maw and Mr. Mee have seen minute craters on the borders of these obscure formations.  In addition to the objects just specified, there is a fairly conspicuous crater, d, on the N.E. quarter of the floor, and a very large number of others distributed on its surface, which is also traversed by a network of light streaks, that have recently been carefully recorded by Mr. A.S.  Williams.  A cleft, from near Reaumur A, traverses the N. side of the floor, and runs up to Ptolemaeus d.

ALPHONSUS.—­A large walled-plain, 83 miles in diameter, with a massive irregular border abutting on the S.S.E. side of Ptolemaeus, and rising at one place on the N.W. to a height of 7000 feet above the interior.  The floor presents many features of interest.  It includes a bright central peak, forming part of a longitudinal ridge, on either side of which runs a winding cleft, originating at a crater-row on the N. side of the interior.  There is a third cleft on the N.W. side, and a fourth near the foot of the E. wall.  There are also three peculiar dark areas within the circumvallation; two, some distance apart, abutting on the W. wall, and a third, triangular in shape, at the foot of the E. wall.  The last-mentioned cleft traverses this patch.  These dusky spots are easily recognised in good photographs of the moon.

ALPETRAGIUS.—­A fine object, 27 miles in diameter, closely connected with the S.E. side of Alphonsus.  It has peaks on the W. towering 12,000 feet above the floor, on which there is an immense central mountain, which in extent, complexity, and altitude surpasses many terrestrial mountain systems—­as, for example, the Snowdonian group.  The massive barrier between Alpetragius and Alphonsus deserves careful scrutiny, and should be examined under a moderately low morning sun.  On the E., towards Lassell, stands a brilliant light-surrounded crater.