ARAGO.—­A much larger formation, 18 miles in diameter, N. of the last, with a small crater on its N. border, and exhibiting two or three spurs from the wall on the opposite side.  The inner slopes are terraced, and there is a small central mountain.  There are two curious circular protuberances on the Mare E. of Arago, which are well seen when the W. longitude of the morning terminator is about 19 deg., and a long cleft, passing about midway between them, and extending from the foot of the E. wall to a small crater on the edge of the Mare near Sosigenes.  Another cleft, also terminating at this crater, runs towards Arago and the more northerly of the protuberances.

CAUCHY.—­A bright little crater, not more than 7 or 8 miles in diameter, on the W. side of the Mare Tranquilitatis, N.E. of Taruntius.  It has a peak on its W. rim considerably loftier than the rest of the wall, which is visible as a brilliant spot at sunrise long before the rest of the rampart is illuminated.  On the S. there are two bright longitudinal ridges ranging from N.E. to S.W.  These stand in the position where Neison draws two straight clefts.  The Cauchy cleft, however, lies N. of these, and terminates, as shown by Schmidt, among the mountains N.E. of Taruntius.  I have seen it thus on many occasions, and it is so represented in a drawing by M.E.  Stuvaert (Dessins de la Lune).  There is a number of minute craters and mounds standing on the S. side of this cleft, and many others in the vicinity.

JANSEN.—­Owing to its comparatively low border, this is not a very conspicuous object.  It is chiefly remarkable for the curious arrangement of the mountains and ridges on the S. and W. of it.  There is a bright little crater on the S. side of the floor, and many noteworthy objects of the same class in the neighbourhood.  The mountain arm running S., and ultimately bending E., forms a large incomplete hook-shaped formation terminating at a ring-plain, Jansen B. The ridges in the Mare Tranquilitatis between Jansen B. and the region E. of Maskelyne display under a low sun foldings and wrinklings of a very extraordinary kind.

MACLEAR.—­A conspicuous ring-plain about 16 miles in diameter.  The dark floor includes, according to Madler, a delicate central hill which Schmidt does not show.  Neison, however, saw a faint greyish mark, and an undoubted peak has been subsequently recorded.  I have not succeeded in seeing any detail within the border, which in shape resembles a triangle with curved sides.

ROSS.—­A somewhat larger ring-plain of irregular form, on the N.W. of the last.  There are gaps on the bright S.W. border and a crater on the S.E. wall.  The central mountain is an easy feature.