On the broken N. flank of Guerike is a number of incomplete little rings, all open to the N.; and E. of these commences a linear group of lofty isolated mountain masses extending towards the W. side of Parry, and prolonged for 30 miles or more towards the north.  They are arranged in parallel rows, and remind one of a Druidical avenue of gigantic monoliths viewed from above.  They terminate on the S. side of a large bright incomplete ring (with a lofty W. wall), connected with the W. side of Parry.

PARRY.—­A more complete formation than Guerike.  It is about 25 miles in diameter, and is encompassed by a bright border, which, at a point on the E., is nearly 5000 feet in height.  It is intersected on the N. by passes communicating with the interior of Fra Mauro.  There is a crater, nearly central, on the dusky interior, which, under a low sun, when the shadows of the serrated crest of the W. wall reach about half-way across the floor, appears to be the centre of three or four concentric ridges, which at this phase are traceable on the E. side of it.  There is a conspicuous crater on the E. wall, below which originates a distinct cleft.  This object skirts the inner foot of the E. border, and after traversing the N. wall, strikes across the wide expanse of Fra Mauro, and is ultimately lost in the region N. of this formation.  Parry A, S. of Parry, is a very deep brilliant crater with a central hill and surrounded by a glistening halo.  A cleft, originating at a mountain arm connected with the E. side of Guerike, runs to the S. flank of this object, and is probably connected with that which skirts the floor of Parry on the E.

BONPLAND.—­A ruined walled-plain with a low and much broken wall, which on the S.W. appears to be an attenuated prolongation of that of Parry.  It is of the linear type, the formation approximating in shape to that of a pentagon.  The floor is crossed from N. to S. by a fine cleft which originates at a crater beyond the S. wall, and is visible as a light streak under a high light.  Schmidt shows a short cleft on the W. of this.

FRA MAURO.—­A large enclosure of irregular shape, at least 50 miles from side to side, abutting on Parry and Bonpland.  In addition to the cleft which crosses it, the floor is traversed by a great number of ridges, and includes at least seven craters.

THEBIT.—­A fine ring-plain, 32 miles in diameter, on the mountainous W. margin of the Mare Nubium, N.E. of Purbach.  Its irregular rampart is prominently terraced, and its continuity on the N.E. interrupted by a large deep crater (Thebit A), at least 9 miles in diameter, which has in its turn a smaller crater, of about half this size, on its margin, and a small central mountain within, which was once considered a good optical test, though it is not a difficult object in a 4 inch achromatic, if it is looked for at a favourable phase.  The border of Thebit rises at one place on the N.W. to a height of nearly 10,000 feet above the interior, which includes much detail.  The E. wall of Thebit A attains the same height above its floor, which is depressed more than 5000 feet below the Mare.