Slate in the United States - Dale, T. Nelson (Thomas Nelson), 1845-1937.; Hillebrand, W. F. (William Francis), 1853-1925.; Eckel, Edwin C. (Edwin Clarence), 1875-1941.; Coons, Altha Titsworth (Washington, Govt. print. off., 1914)
Many plates printed on both sides of leaves.
"The present bulletin is not only a corrected and revised ed. of bulletin 275, but contains also the results of ... recent discoveries and studies."
"Bibliography of slate": p. 205-213.
Keywords: Slate