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The Paleobotany of the Bloomington, Indiana, 

 Quadrangle. 



T. F. Jackson. 



The fossil plants herein discussed are, with three exceptions, Penn- 

 sylvania forms and were collected principally from two localtiies in the 

 Bloomington, Indiana, Quadrangle. The greater part of them were ob- 

 tained from a shale bed about one-fourth mile southeast of the Yoho 

 School. This bed was made up of a succession of thin, bluish-gray clay- 

 shales interstratified with thin sandy layers, with nodules of iron ore 

 irregularly distributed throughout the entire bed. The shale layers were 

 very soft and plastic when wet and both the shale layers and sandy layers 

 were rather hard and very brittle when dry. One of the shale layers 

 was very highly impregnated with iron oxides, and from this layer the 

 best fossils were obtained. The entire bed attains a thickness of eight 

 to nine feet. 



The remainder of the Pennsylvanian forms were obtained from a thin, 

 ferrugineous sandstone layer and an overlying sandstone layer, about 

 one-fourth mile southeast of Cincinnati. Molds and casts of Lepidodeudron 

 and Oalamite forms were collected from the latter. The ferrugineous 

 sandstone layer contained a number of Trigonocarpon and a few Carpo- 

 lithes forms. 



Loose sandstone fragments of fossil plants, apparently of Pemisyl- 

 vanian age, were noted in a number of places in the southwestern part 

 of the Quadrangle, but, as their exact horizon could not be ascertained, 

 those forms are not included in the following lists of species. 



A few fragments of Mississippian forms were noted in the central 

 and northern part of the west half of the Quadrangle. Those plants were 

 very poorly preserved and at but one place were fossils obtained in a 

 state of preservation such that identification was possible. Three species 

 in a fair state of preservation were found in a sandstone layer a few feet 

 above the Mitchell limestone, about one-half mile west of Whitehall. 



