CHAP. 2.] PHYSICAL STRUCTURE. 25 
scarp (at about the same level as the first from Paipully) or edge of the 
Oopalpad plateau, which gently descends to and flanks the Khoond-air 
valley. The flat bottom of this great hollow averages from 6 to 800 
feet above the sea. The Nullamullays are then reached, and they rise 
up in sharp undulations to a height of 2,250 feet; to descend again 
with less rapid sweeps to the long north and south set of Kullsapawd and 
Porenaumlah* valleys with their intermediate ridges, which are only 
separated from the plains of Nellore by the Yellaconda. The crest of 
the fringing ridge of the Eastern Ghats is 1,000 feet or so above the 
sea at this point; and at 800 feet below, the Nellore plains begin to 
slope away towards the coast. 
The next section, No. 3, is taken along a parallel of latitude just 
ik csation. a few miles north of Cuddapahtf town. Here 
the great central valley is very apparent, showing 
a plain of from 450 to 500 feet elevation; the edge of the Mysore 
plateau is 800 feet above the sea, and the western scarp overlooking it 
rises up in the Polleonda Trigonometrical Station to about 2,000 feet. 
On the eastern side of the Cuddapah basin, the Nullamullays decrease 
in elevation as they are traced southwards; while the Yellaconda ridge 
is very low, the gap through which the Penn-air river flows being near 
this pomt. Beyond this the Nellore country commences to slope away 
from the basis of the hills, at scarcely 200 feet above the sea. 
Section No. 4 is taken still further to the south, through the 
parallel of Rachotee{ (on the edge of the Mysore 
plateau), and there the superficial outline of the 
Rachotee section. 
country much decreases in length horizontally co-equally with the 
* In the north-east part of the Cuddapah District; about 15° N. Lat., 78 58’ E. Lon., 
and 660 feet (Cullen) above the sea. 
+ According to the late Genl. Cullen, 490 feet above the sea. 
f In the sub-division of the Cuddapah District, about 30 miles south of the town, 
D (39) 
