i6 Natural History Bulletin. 



ted after S. parryana abandoned the struggle. They range a 

 foot or two above the spirifer bed, but brachiopod life soon 

 ceased, and the sandstone through several feet of its thickness 

 shows no traces of fossils. 



There is but a single fish tooth in the collections from the 

 sandstone, and it is apparantly identical with an undetermined 

 species occuring in the Hamilton limestones at Solon and Iowa 

 City. 



The most significant facts recorded in the Devonian and 

 Carboniferous strata of Muscatine county have been recog- 

 nized by all geologists who have personally examined the re- 

 gion. These facts are detailed with scientific minuteness in 

 the reports on the geology of Iowa and Illinois. Briefly 

 stated, we have evidence that at the close of the Hamilton 

 period, after the limestone and sandstone strata had been 

 finished the sea retired southward and westward, and Musca- 

 tine county became a part of the growing continent. The 

 strata of the Kinderhook, Burlington, Keokuk and St. Louis 

 epochs were successively deposited in the gradual!}' retreating 

 sea, and at successively greater and greater distances from 

 Muscatine county. All this while the agents of erosion were 

 at work in what is now the region of Pine Creek and Mont- 

 pelier. There is absolutely no evidence that the region ever 

 received an}' Sub-carboniferous deposits. The epochs of the 

 Lower and Upper coal-measures seem successively to have 

 followed the St. Louis epoch in Iowa, and the loM^a coal basin 

 proper, occupies an area to the south and west of the region 

 occupied by the St. Louis group. While, however the Car- 

 boniferous shales and sandstones about Buffalo and Mont- 

 pelier are of the same age as what is known as the Middle or 

 Upper coal-measures, I do not believe that any very direct 

 connection exists between them and our Iowa coal field. The 

 connection seems more direct with the Illinois coal field. 

 After a period of subaerial exposure, represented by the strata 

 of the Sub-carboniferous and probably bv a considerable por- 

 tion of the coal-measures, the region about Pine Creek that 

 had been left bare at the close of the Devonian, was, by 



