310 ERWIN HINCKLEY BARBOUR 
Fic. 1.—Glaciated surface, carboniferous limestone, Weeping Water, Nebraska, 
badly shattered by a blast, yet plainly showing striae and grooves. ‘The -central 
groove varies from three to four inches in width, and is about one and one quarter 
inches deep, and runs south 29° west. From a photograph by the writer. 
noted, being three inches across and one and a quarter deep, ran 
south twenty-nine degrees west. There were numerous ragged 
grooves varying from one quarter to one half inch in depth, and 
innumerable closely crowded parallel striae. The whole surface 
was reduced to a plane, portions of which were well polished. 
Upon it rested a thin layer of drift consisting of a little clay, 
numerous large pebbles and an occasional bowlder of Sioux 
ee 
