52 
IOWA ACADEMY OP SCIENCES. 
The fourth division, that of fossil diatoms in Iowa, is 
reserved for another paper. 
The number of counties in the state which have been visited 
by the author, and those from which material has been 
received, number twenty -nine. * At some future time we expect, 
to present to the people of Iowa who are interested in this 
work, a descriptive list of all the species of diatoms found, 
with a photograph of each. 
REPORT ON A FOSSIL DIATOMACEOUS DEPOSIT IN 
MUSCATINE COUNTY, IOWA. 
BY P. C. MYERS. 
Previous to the present year no fossil diatoms had been 
found in Iowa. On October 20, 1898, Prof. J. A. Udden, of 
Rock Island, 111., while engaged in work for the Iowa Geologi- 
cal survey, found and sent to Prof. S. Calvin, of the State Uni- 
versity, some diatomaceous earth. This material was taken 
from below the loess in Muscatine county, Iowa, and was 
turned over to the author for examination. It was of a dull, 
yellow color, composed of sand and decayed vegetable matter 
and a few diatoms. 
The species, with their general distribution and habitat, are 
as follows: 
Navicula abaujenssis PauL Fresh water fossil in Hungary. 
NaviciUa borealis (Elir.) Kuetz. In fresh water, cataracts, 
rivers and wet moss, all over Europe and America. 
Navicula gibba ( Elir. ) Kuetz. Everywhere in fresh water. 
Navicula major Kuetz. A cosmopolitan species in fresh 
water. 
Navicula nobilis (Elir.) Kuet^., var. dactylus (Elir.) V. H. In 
bogs and fossil. 
Navicula rupestris (Finn.) Hantz. On wet rocks. 
Navicula placentula (Elir.) Kuetz. In rivers in Europe and 
America; also fossil and marine. 
* As there are many places in the state still unexplored, I desire at this time to say 
to the members of the Academy that I should be glad of their co-operation in this 
matter. 
