i86 



G. H. SQUIER 



boring circs are very wide at the outer margins, but narrow to ridges 

 of only a few feet in width at the points where they join the pri- 

 mary bluffs. In some cases these connecting ridges have been so 



Fig. 5. — Sketch map of a portion of the same valley as shown in Fig. 4, joining 

 that on the north — (east end). It shows a spur extending out from one of the angles 

 of a limestone-covered bluff and having its top covered with limestone debris. It 

 appears to extend downward somewhat on the east side, but, on account of the 

 increasing thickness of the loess, it cannot be told how far. At b a spur of very- 

 similar height and form holds almost identical relations to its primary bluff, but it is 

 entirely destitute of limestone debris. It is evident, therefore, that one has been 

 subject to the action of some agent which did not effect the other. Scale 500' to 

 an inch. Contour lines at intervals of 50 ' . 



worn away as to form a considerable sag. For convenience, I 

 will speak of these secondary hills between circs as buttresses. 



For the purpose of illustration I have selected one of the 

 finest of these, which is shown in contour lines in the accom- 



