IOWA ACADEMY OF SCIENCES. 53 



Eunotia dloclon (Ehr.). Rivers, springs, rapids, on wet rocks 

 and fossil. 



Eunotia gracilis (Ehr.) Rabeuli. In boggy, swampy places. 



Eunotia major (Win. Sm.) Rabeuh. In fresh water every- 

 where. 



Stauroiiers phoeneceinteron (Nitz.) Ehr. Cosmopolitan. 



Cystopleura gibba (Ehr.) Kimze. Common in fresh water; also 

 fossil and marine. 



Ct/nibeJla ei/nibiforinis (Kiietz.) Breb., var. parva (Win. Sin.) V. 

 H. Common everywhere in fresh water. 



Hantzschia. ainjjhyoxis (Ehr.) Grun. Common everywhere in 

 fresh water. 



Judging from the above and from evidence which does not 

 appear here, /. e., the comparative number of individuals in 

 each species, the condition was probably that of a shallow 

 bog, subject to gentle overflows from some creek or river. 



DIATOMACEOUS EARTH IN MUSCATINE COUNTY. 



BY J. A. UDDEN. 



While at work on the geology of Muscatine county last sum- 

 mer, the writer found some diatomaceous earth in tne south 

 bank of the creek which runs west near the south line of sec- 

 tion fourteen, in Cedar township. It is associated with a peaty 

 layer, which overlies it, and which appears somewhat dis- 

 turbed. This peat is overlain by tine laminated sand and silt, 

 which here forms the base of the loess. Below the peat bed 

 and the diatomaceous layer there is a white sand without a 

 trace of ferruginous stains. Boggy conditions are indicated, 

 or perhaps the conditions of a lake or pond. The diatomace- 

 ous earth itself does not lie in a continuous layer, but in a 

 broken layer, or in small pockets, which are scattered. It has 

 a peculiar dull, pink color, and this has lately enabled the writer 

 to find small lumps of it in the peaty soil under the loess in Scott 

 county, near Davenport. It was from this loess that the 

 remains of a mastodon have been reported by Mr. Pratt. 



