390 W. G. WUOLNOUGH. 
example. It appears to the author, however, that Jutson 
has not fully appreciated the significance of these valleys, 
which are extremely widely developed in the Darling 
Range area. They form a series of sub-parallel troughs, 
roughly meridional in direction, and parallel with the 
general “‘grain’’ of the country. They are very wide in 
proportion to their depth, that is, are highly mature, and 
are of the utmost economic importance, since they consti- 
tute the arable portion of the ‘‘Wheat Belt’’ of Western 
Australia. They are carved out of the laterite covered 
plateau, and their bottoms lie at least 200 feet below its 
level. The floors and sides are clear of laterite coating, 
and the basement granites and “‘greenstones’’ of the 
country are exposed. 
The author regards these great longitudinal valleys as 
evidence of a slight uplift which occurred after the forma- 
tion of the Darling Peneplain, and before its elevation to 
its present altitude. This uplift was of small amount, but 
sufficed to rejuvenate the drainage, and to reinstate the 
normal processes of corrosion; and the land surface 
remained in a stable condition long enough for advanced 
maturity of erosion to be attained, without production of | 
a complete peneplain. For this reason the author suggests. 
the name ‘* Mature Valley Level’’ for the partial peneplain 
which was produced under the circumstances described. 
If a local name is preferred instead of that suggested, (and 
such is probably better, since there are other mature valley 
levels in Australia and elsewhere) the name ‘‘ Meckering 
Level’’ may be substituted, since the prosperous agricultural 
townof Meckering occupies one of these valleys. Meckering 
is preferred to Beverley, York or Northam, as being more 
distinctively Western Australian, though the mature valley 
topography is even more marked at the towns mentioned. 
At the time of the principal Darling Range uplift, these 
mature valleys were occupied by long, gently-flowing 
