24, REPORT—1868. 
line of cliffs ITI A¢ 8, JIT A*5, ITV A*8. From thence the “ fault ” extends 
to the E. edge of Reaumur ; its face is towards the E. 
This “fault” is not unlike, but lower in altitude than, Straight Wall. It 
is not so prominent an object as Straight Wall, which, occurring throughout 
its entire length on a plain, is very easily seen, whereas the “fault ” now 
under notice traverses a variety of surface, and is moreover surrounded by 
striking and conspicuous objects, among which it may readily be overlooked. 
It is nevertheless an interesting object. 
Craters.—The following is an enumeration of the craters and craterlets 
at present recorded as existing on or within the boundaries of the Terra 
Astronomica, as now described. 
Area IV AS. 
TGV AS...) Inthe S.Boangle 20... s.0u.5. B. & M.G.| L. | Ph. 
ZV AS°,..| On SH. portion S.W..of LY AS! |. oe ernie L.. |-Ph. 
SALVE CAG 2 nl) 55 bus’ mh POOL EASS: 
Ara elVEAS * oh | sas. 55 »  &.W. of LV AS!..| B. & M. 1B fei. 
Bg MLA Ns ie Sr SEU rae Seen tent B. & M.._ |Lx).| Ph. 
(GI fel LAV NCS A A oN. of LV AS). . | Bi dy Mek ai eh 
ea LY (NS CPL es at 57a els OL WVCASS Seb wave 
Sov: ASe24. Wiloa uss 55. WV 6 08, DVLAS%, 3; |, Boaccall. 
These seven craters form a fine 
and conspicuous group. 
9.| IV As}3 ..| Between LV A$! and Ptolemeeus. .| B. & M. 
10.) IV As!4 .. i 98 FA 35 B. & M. 
11.| IV Ag35 ., 3 53 x a B. & M. 
12.| IVAS$18 .. ae op a e B. & M. 
13.| IV A$}9 .. os BS oe a B. & M. 
These five craters form a “row” 
connecting IV A¢! with the 
N.W. border of Ptolemzus. 
B. & M. give sia. See letter- 
press, areas LY A“, TV AS, p. 23. 
IV As}9, The “ crater-row” ap- 
pears as a lucid streak on the 
photogram, but is easily re- 
solvable in the telescope. 
14,| IV A¢!2l..| N. of IV Ag 28, 
15.| IV Ags. .| N. of IV Ao}4. 
16.| IV As 49 ..| On the 8. end of IV A¢ 47, 
17.| IV A¢®9 ..| A crater? W. of the mountain- 
arm, [IV As 47, 
18.| ITV Ag12,.| S.S.W. of IV A$ 389, 
19.| IV Ag U8. .| S.E. of IV As 2, 
a This crater is one of a class which has been but recently suspected to exist on the 
moon, and of which the crater Zinné in the Mare Serenitatis was probably the first 
observed. ‘The principal characteristic of this class of objects consists in the occasional 
obscuration of the crater-form, nothing being seen but a white spot, which is very often 
indistinct and undefined in its outline. In the case of Linné this white spot has been 
observed to present itself rather suddenly. See Astronomical Register, No. 60, Dec. 1867, 
p- 254. The observations of TV A$®9 will be found in the same work, No. 62, Feb. 1868, 
p. 43, and also in the Proceedings of the Manchester Literary and Philosophical Society, 
vol. vii. p. 73. 
