Some twenty years ago Dr. E. O. Ulrich asked the writer to work out the large graptolite collection brought together by the U. S. Geological Survey and deposited in the National Museum. The collection is especially rich in material from Virginia, Alabama, Tennessee, Arkansas, and Oklahoma, obtained by Ulrich and his assistants, notably Mr. R. L. Mesler; and in material from Texas, Nevada, Idaho, British Columbia, and Alaska collected through the efforts of C. D. Walcott, E. Kirk, A. F. Buddington, and others who worked in these regions. It also contained a fine collection of Point Levis, Quebec, material made by C. D. Walcott and one of authentic material from the same locality, identified by James Hall, and sent by the Geological Survey of Canada in exchange.
These valuable collections, filling some 120 drawers in double and threefold layers were supplemented by extensive collections of material made by Canadian geologists in all parts of Canada. Especially important were those of H. M. Ami, E. M. Kindle, C. S. Evans, and P. S. Warren. The writer has already published reports on some of these collections, especially those of Walcott, Evans, and Warren.
To these collections were added gradually, as study material that furnished descriptions and drawings, numerous smaller ones sent by students from all parts of North America, as from Newfoundland, Quebec (including Gaspé), New Brunswick and Nova Scotia, Maine, where Dr. Olaf A. Nylander proved an undefatigable collector, Vermont, New York, New Jersey, Pennsylvania, Tennessee, Ohio, Indiana, Michigan, Illinois, M. . .