261 
of the Mississippi. Normally the point where a tributary valley joins a 
larger one is marked by a notch in the wall of the latter, but in some cases 
a bisected spur appears instead. The delta of Canadice outlet, mentioned 
above, furnishes a good example. A delta at Lake Warren level, near 
Hast Bloomfield, what is left of it, has the form of a single narrow tongue 
more than a half mile long. Such lateral deposits of a stream may be 
called levee deltas. 
Hanging deltas have been the chief guides to geologists in mapping 
the outline of temporary glacial lakes, but they are worthy of more careful 
study as simple and well displayed specimens of constructional shore 
forms.® 
State Normal School, 
Terre Haute, Ind. 
2 i | 
8 Nearly all the features mentioned in this paper may be found upon the Way- 
land, Naples, Honeoye and Canandaigua sheets of the Topographic Map of United 
States. 
