Personal dud Scientific News. 273 
The Extent and Lapse of Time Represented by Unconformities. 
Prof. C. R. Van Hise, U. S. Geological Survey. 
The Phylogeny of Plants. Prof. Lester P. Ward, U. S. Geological 
Survey. (Absent; read by title.) 
The Phylosreny of the Classes of Vertebrates. Dr. O. Jaekel, Berlin , 
Germany. (Absent; read by title.) 
Restoration of Clidastes (illustrated). Prof. S. W. Williston, Uni- 
versity of Kansas. 
In the discussion following these papers, Prof. Van Hise re- 
plied to Dr. Selwyn that the term Algonkian is more compre- 
hensive than Huronian. Above the Huronian system it in- 
cludes the Keweenawan of the Lake Superior region. Its 
time extent probably surpasses the Cambrian, and is com- 
parable to the whole of the Paleozoic. The grand time di- 
visions as eras, according to the terminology used by the 
United States Geological Survey, are the Archean, the Proter- 
ozoic (receiving the Huronian, Keweenawan, and other Al- 
gonkian series which may hereafter be discriminated), the 
Paleozoic, Mesozic, and Cenozoic. 
The question proposed for special discussion, terminating 
this session, was: What are the Principles and Criteria to be 
observed in the restoration of Ancient Geographic Outlines? 
Mr. W J McGee displayed maps of the Lafayette, Columbian, 
and Champlain submergences of the coastal border through the 
Eastern, Atlantic, and Gulf states, and reviewed the princi- 
ples by which he has restored its Neocene and Pleistocene 
geography. 
Mr. C. D. Walcott spoke of his studies of the Cambrian 
outlines of North America, from which he thinks the conti- 
nent to have been chiefly permanent, though undergoing many 
oscillations and minor changes, from that very early time. 
Prof. H. S. Williams suggested that small land uplifts in 
areas of narrow and shallow seas may change oceanic cur- 
rents and thus produce great changes of the marine faunas. 
The venerable Prof. James Hall, coming in at this time, 
was warmly welcomed and spoke briefly of his work for 
geology, which began sixty years ago. Fifty-three years ago 
he attended the first meeting of the Society of American Nat- 
uralists and Geologists, at which twenty were present. Thai 
society after about ten years became the American Associa- 
tion for the Advancement of Science. 
Prof. T. ('. ( -hamkeklin thinks that during the Lafayette 
epoch tile sea extended up the Mississippi embayment to 
Cairo. The deposition of the Loess along the Mississippi 
valley was dependent partly on lacustrine conditions, and 
partly on broad river Hoods; but later, when the moraines 
were formed, the land stood at its present elevation or higher. 
Two Quaternary epeirogenic uplifts of moderate vertical 
amount are recognized in this central part of the continent, 
