In many sections of the country are found not only chipped implements, but other implements heavily coated with patina, which is an incrustation accruing by time alone. There are other worn specimens which appear very old. Select some of these and compare them with objects from the Mandan or Iroquois sites, or even from the mounds in the Ohio Valley, and one will observe the apparent difference in the age of these specimens. The Mandan pottery and some of the Iroquois pottery are even at this late date coated with soot. There is no soot on the mound pottery. Along the Atlantic Coast, and in the South, flint implements are sometimes coated with patina. In Florida shell heaps are occasionally found skeletons at great depth. Mr. Clarence B. Moore considered the lower strata of the larger shell heaps to be very old. There was a skull found by Dr. Wyman during the course of his exploration many years ago in the base of a shell mound in Florida.[35] I present a picture of it in Fig. 717. The cranium is heavily incrusted by cemented shells. Such a burial must be of great age. These shell heaps accumulate very slowly during the occupancy of the sites by many generations of Indians. This skull, and the skull found at Lansing, Kansas, at a depth of twenty-five or thirty feet, and other finds, are evidences of considerable antiquity. Dr. Hrdlička has said that the Lansing man was of the same type as the modern Indian. This does not mean that it is modern, for Assyrian and Egyptian crania five or more thousand years old have been taken from the tombs, and it would require experts to distinguish them from crania of living people. Prof. Edward H. Williams, Jr., of Woodstock, Vt., suggested to me that an expert analysis be made of the surface of certain problematic forms and ornaments finished and unfinished. Therefore, I gave to Prof. Williams some forty objects from our Andover collection, and he made a careful examination, as did his friend Prof. John D. Irving of Lehigh University, who is secretary of the Geological Society of America, and an expert in such matters. Some of these specimens are found to be old, a few very old, and others more or less recent. I shall quote a few of his observations. The numbers refer to catalogue numbers in our books:— “22517—From Georgia. This is a fine-grained diabase. Prof. Irving reports that the ophitic structure is very well marked. This object has been buried for some time, and the surface is weathered, and has been pitted since it was worked. “23449—Syenitic Gneiss. The feldspar had begun to kaolinize before the pebble was worked. Since working the surface has been considerably etched, and the hornblende is left rising above the surface. This black mineral has also been decomposed since working, and the iron component has rusted and stained the horn.