330 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
rises further north by a faded scarp of gentle slope. Sandstone ledges 
are abundant along the western base of the spur; they are unusually 
steep, in part because of the eastward dip of the strata, and in part be- 
cause of a certain amount of under-cutting by the Westfield when it ran 
beneath them. The eastern side of the spur is not trimmed close to the 
defending ledges, but illustrates the unsymmetrical relations shown in 
Figure 31. Widely as the river has swung from side to side in the 
basin further west, it was here strongly constrained. Not only so: 
Westfield river has been somewhat impelled northward by the 
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Fig. 38. 
entrance of Little river from the south (west of the area shown in 
Figure 38) ; and it is probably in part at least on this account that the 
basin has been so well broadened northward ; yet on every sweep or 
swing against the sandstone reef, the river was not only restrained 
from further northward conquest at that point, but was deflected 
obliquely southward across the valley. It is very probable that the 
excavation of the subordinate basin, C, is due to this cause, for it is 
opened further to the south than to the north. Three strong south- 
ward loops of the river, D, E, F, (including the present one) are here 
recorded; and it can hardly be by chance that the river has thus 
