HELL.—­A prominent ring-plain, about 18 miles in diameter, on the E. side of the great plain.  There is a central mountain and many ridges within.

BALL.—­A somewhat smaller ring-plain on the S.E. edge of the great plain, with a lofty terraced border and a central mountain more than 2000 feet high.  There are two large irregular depressions on the W. of the formation, a crater on the S., and a smaller one on the N. wall.

PITATUS.—­This remarkable object, 58 miles in diameter, with Hesiodus, its companion on the E., situated at the extreme S. end of the Mare Nubium, afford good examples of a class of formations which exhibit undoubted signs of partial destruction, from some unknown cause, on that side of them which faces the Mare.  On every side but the N., Pitatus is a walled plain of an especially massive type, the border on the S.E. furnishing one of the finest examples of terraces to be found on the visible surface.  On the S.W., two parallel rows of large crateriform depressions, perhaps the most remarkable of their kind, extend for 60 miles or more to the W. flank of Gauricus.  On the N.W., the rampart includes many curious irregular depressions and craters, and gradually diminishes in height, till, for a space of about 12 miles on the N., there can hardly be said to be any border at all, its site being marked by some inconsiderable mounds and shallow hollows.  There is a small bright central mountain on the floor, and, S. of it, two larger but lower elevations.  A distinct straight cleft traverses the N.W. side of the interior very near the wall, to which it forms an apparent chord, and a second cleft occupies a similar position with respect to the bright N.E. border.  A narrow pass forms a communication with the interior of Hesiodus.

HESIODUS.—­This walled-plain, little more than half the diameter of the last, has an irregular outline, and for the most part linear walls, which on the S. are massive and lofty (4000 feet), but on the N. very low, and broken by gaps.  There is a fine deep crater on the S. border, and a small but distinct crater on the floor, nearly central, the only object thereon which I have seen, though Schmidt draws a smaller one on the W. of it.

A mountain abutting on the N.E. side of Hesiodus is the W. origin of one of the longest clefts on the moon.  Running in an E.S.E. direction, it traverses the Mare to a crater near the W. face of the Cichus mountain arm, reappears on the E. side of this object, and is finally lost amid the hills on the N. of Capuanus.  The W. section of this cleft is coarser and much more distinct than that lying E. of the mountain arm.

GAURICUS.—­A large walled-plain S. of Pitatus, about 40 miles in diameter.  The border is very irregular, and, according to Neison, consists on the E. of a precipitous cliff more than 9000 feet high.  It is surrounded by a number of large rings on the S., and has several considerable small depressions on its N. border.  There is apparently no prominent detail on the floor.  Schmidt shows some ridges and craterlets.