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DAVIS: RIVER TERRACES IN NEW ENGLAND. 390 
upon previously buried spurs. Brown’s spur is peculiar in being closely 
trimmed on the down-valley side as well as on the up-valley side. 
Prospect spur has a terraced re-entrant, C, scoured out at mid-height 
with small radius and large arc, far back on its up-valley side; that is, 
a meander of the river has there been twice compressed against defend- 
ing ledges, after the style of Figure 30. Elsewhere the meanders 
seem to have slipped past the defending ledges, after the style of 
Figures 25 to 28. 
The terraces on the south side of the valley are in several cases de- 
termined indirectly by the ledges on the north side. This is most 
distinctly the case where the river formerly swept forward from the 
lowest and furthest forward of the Pochassic ledges, M, and consequently 
cut out one of the deepest re-entrants on the south side of the valley, P. 
A single scarp now descends from the high-level plain into this strong 
recess. Similar but less manifest relations are suspected elsewhere ; 
thus K’, K”, K on the north may correspond with S/, S!’, S’”’ on the 
south. Conversely, a number of low-level terraces remain on the south 
side of the valley south of Brown’s spur, perhaps because the repeated 
northward swings of the river into the largest northward re-entrant, 
that between Brown’s and Prospect spurs, have not required their 
removal. _The numerous free cusps here found exhibit the features al- 
ready deduced as of common occurrence. Jt is intended to make 
a close measurement of the slopes of these terrace plains in the hope of 
correlating the now separate remnants of single flood plains, and thus 
tracing the history of the terracing process in some detail. 
Litrte River. A few words may be said about Little river, although 
the southern side of its valley has not been closely studied. The valley 
of this stream is divided into three sections by two barriers of sandstone, 
next up-stream from which are considerable bodies of till. The till has 
been cut down to grade with the sandstone barriers, but the valley in 
the till is held to a small width, practically without terraces. Relatively 
few terraces are found even where the valley is bordered by stratified 
drift. In explanation of this it should be noted that Little river is 
smaller than the Westfield, and that a small stream must be hurried in 
attempting to keep pace with the degrading action of its master. Hence 
the smaller stream will have little opportunity for lateral swinging and 
terracing so long as it runs through loose drift to a more actively degrad- 
ing master stream. There are two conditions under which opportunity 
for lateral swinging will be presented to the smaller stream. First, when 
the master stream has effectively ceased degrading its valley. _ This is 
