588 



IOWA ACADEMY OP SCIENCE Vol. XXV, 1918 



gTayisli Conglomerate one to two feet thick, figure 194. The peb- 

 bles are mostly limestone, fairly well smoothed by attrition, and 

 are rather small, the larger ones being not much over half an inch 

 in diameter. Under the conglomerate lie the shales of the Des 

 Moines stage locally colored red or lighter shades. At other 

 places near by the conglomerate outcrops immediately beneath 

 the drift, fi^re 195. The gypsum either has been removed by 

 erosion or solution or was not deposited. The significant feature 

 about this conglomerate, however, is its fossil content, and this it 







¥.dlhMit!>^^^ 



Fig. 195. — The conglomerate which lies immediately under tlie gypstim in 

 the ravine opposite Two Mile creek, below Fort Dodge. The conglomerate is 

 fossiliferous here. 



is which makes it of peculiar value in relation to the gypsum. 

 Professor A. 0. 'I'homas of the Department of Geology of the 

 State University visited the gypsum region with the writer on 

 a later trip and a number of fossils were collected from the con- 

 glomerate. Mr. Thomas after studying this collection and com- 

 paring it with type forms wrote as follows: "The basal con- 

 glomerate fauna is very evidently of Missouri age although I am 

 not ready to say so unequivocally since so many Pennsylvanian 

 forms have a habit of continuing on into the Permian. I have 



