390 Tlic American Geologist. December, i899 
cuously from a fresh and unweathered exposure anywhere in this re- 
gion there would be one or more pebbles of this kind. 
It does not seem likely that these pebbles can have come from the 
Colorado formation in the western part of Iowa. This would necessi- 
tate an extended transportation too nearly from west to east tO' have 
taken place in the Kansan ice field. On the other hand, these frag- 
ments of shale seem too soft and too frequent of occurrence to be re- 
garded as a residue of material picked up from the Cretaceous in the 
extreme northwest and they appear too widely and too uniformly dis- 
tributed to be derived from any concealed outlier in the region here. 
In this same drift I have also found broken crystals of staurolite, 
which Dr. C. P. Berkey regards as similar in appearance to crystals 
of the same mineral occurring in abundance in metamorphic rocks in 
the Little Falls district and in northern Minnesota. One of these 
crystals was found in Scott county, one near Fruitland in Muscatine 
county, and one twenty miles west from the latter place. In general 
the pebbles of this drift indicate a transportation from the north, with 
a local deflection to the southeast. 
J. A. Udden. 
PERSONAL AND SCIENTIFIC NEWS. 
Dr. Marcus Benjamin rs Giving in "Science" a series 
of biographical sketches of past presidents of the -American 
Association for the Advancement of Science, with occasion- 
al portraits. The issue for November 19th has an excellent 
portrait of John W. Foster, with sketches of Foster, Hunt, 
Smith and others not known as geologists. 
Mr. W. H. Dall has recently returned to Washington, 
after an absence of several months on the Pacific ocean dur- 
ing which he has travelled some 23,000 miles. 
Mr. C. E. Siebenthal, formerly of the University of 
Chicago and now of the Manual Training high school at 
Indianapolis, has completed, and is able to furnish copies of, 
a relief model of Chicago and vicinity. This model brings 
out clearly the contrast between the topography of a drift- 
covered country within and without an old lake bed, and 
the former shore lines about the southwestern end of lake 
Michigan are also shown. 
Dr. a. C. Spencer of the U. S. Geological Survey spent 
the last six weeks of the field season on reconnoisance work 
in southwestern Colorado. He has been tracing the Devo- 
nian of the region and rectifying the earlier mapping. 
