52 IOWA ACADEMY OF 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., w^hile 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 Pant. Fresh water fossil in Hungary. 



Navicula borealis (Ehr.) Kuetz. In fresh water, cataracts, 

 rivers and wet moss, all over Europe and America. 



Navicula fjibba (Ehr.) Kuetz. Everywhere in fresh water. 



Navicula major Kuetz. A cosmopolitan species in fresh 

 water. 



Nivicula nobilis (Ehr.) Kuetz., var. dacti/Ius (Ehr.) V. H. In 

 bogs and fossil. 



Navicula rupestris (Pinn.) Hantz. On wet rocks. 



Navicula placentula (Ehr.) Kuetz. In rivers in Europe and 

 America; also fossil and marine. 



* As there are many places in the state stiU unexplored, I desire at this time to say 

 to the members of the Academy that I should be g-lad of their co-operation in this 

 matter. 



