During charting operations west of the Mississippi Delta area, the United States Coast and Geodetic Survey explored in detail the submarine valley that had been discovered previously in a locality 30 miles south‐west of the Passes. The writer was fortunate in being able to accompany the survey vessel during these operations. The large domes and ridges discovered in the vicinity of the valley were not anticipated and open up a new problem for marine investigations.
This work was assisted by a grant from the Geological Society, which covered expenses incidental to the trip. Thanks are due also to the United States Coast and Geodetic Survey and particularly to Captain F. S. Borden, of the Hydrographer, the vessel on which the survey was made. The coöperation of Dr. Marcus Goldman, Dr. J. B. Reeside, Mr. L. G. Henbest of the United States Geological Survey, and Mr. J. T. Richards . . .