BOUGUER.—­A bright regular little ring-plain, about 8 miles in diameter, N. of Bianchini.

J.F.W.  HERSCHEL.—­A vast enclosed plain, about 90 miles across, bounded on the W. by a mountain range, which here defines the E. side of the Mare Frigoris, on the S. by massive mountains, and on the other sides by a lofty but much broken wall, intersected by many passes.  Within is a large ring-plain, nearly central, and a large number of little craters and crater-pits.  The floor is traversed longitudinally by many low ridges, lying very close together, which at sunrise resemble fine grooves or scratches of irregular width and depth.

HORREBOW.—­A ring-plain of remarkable shape, resembling the analemma figure, standing at the S. end of the mountain range bounding J.F.W.  Herschel on the W. Schmidt shows a crater on the W. wall, near the constriction on this side, and a second at the foot of the slope of the E. wall.

PHILOLAUS.—­A ring-plain 46 miles in diameter, on the N.E. of Fontinelle.  Its bright walls rise on the W. to a height of nearly 12,000 feet above the floor (on which there is a conspicuous central mountain), and exhibit many prominent terraces.  Philolaus is partially encircled, at no great distance, by a curved ridge, on which will be found a number of small craters.

ANAXIMINES.—­A much foreshortened ring-plain, about 66 miles in diameter, on the E. of Philolaus.  One peak on the E. is nearly 8000 feet in height.  Schmidt shows four craters on the W. side of the floor, and a fifth on the S.E. side.  There is a bright streak in the interior, which extends southwards for some distance across the Mare Frigoris.

EAST LONGITUDE 40 deg.  TO 60 deg.

REINER.—­A regular ring-plain, 21 miles in diameter, in the Mare Procellarum, S.S.E. of Marius, with a very lofty border terraced without and within, and a minute but conspicuous mountain standing at the N. end of a ridge which traverses the uniformly dark floor in a meridional direction.  A long ridge extends some way towards the S. from the foot of the S. wall, and at some distance in the same direction lie six ill-defined white spots of doubtful nature.  On the E.N.E. there is a large white marking, resembling a “Jew’s harp” in shape, and farther on, towards the E., a number of very remarkable ridges.  On the W. will be found many bright little craterlets.  A ray from Kepler extends almost up to the W. wall of Reiner.

MARIUS.—­A very noteworthy ring-plain, 27 miles in diameter, in the Oceanus Procellarum, E.N.E. of Kepler, with a bright border rising about 4000 feet above the interior, which is of an uneven tone.  The rampart exhibits some breaks, especially on the S. The outer slope on the W. is traversed by a fine deep valley, distinctly marked when the opposite side is on the morning terminator.  It originates on the S.W. at a prominent crater situated a little below the crest of the wall, and, following its curvature,