No. 150B, twenty-seven feet of the neck of which had been recovered. The skull, or parts of the skull of Apatosaurus were found and apparently we have, at last, the material for settling the doubt as to what kind of a skull and what kind of teeth this animal possessed.

The cut was extended about 140 feet eastward to where it was about 40 feet deep, and we were opening up the region where we hoped to find the other prize, when a section of the river sandstone, 40 ft. wide by 60 ft high, slid on the shale of the older marsh or lake deposits, down into the cut. This mass weighed many hundreds of tons, but in order to insure safety,