110 Kansas Academy of science. 



of all imaginable shapes and sizes, rough vases, large troughs, bunches of fruits, hollow- 

 stems. It is easy to call these concretions. When we have said that, it is all plain ! Is 

 it? What is a concretion? A gathering together of somethings. What was the thing 

 and the force that concreted and arranged the material of these balls, pipes, geodes? 

 We have handled several thousands of these Dacotah concretions and examined many 

 from other formations, and notwithstanding their multiform character we have come to 

 the decided opinion that the origin, the starting point of the great majority — say nine- 

 tenths of these in the Dacotah — is some organic form, mostly vegetable, about which 

 the other material has been arranged in layers more or less concentric. A seed, a fruit, 

 a nut, a twig, a snail-shell, a naked gasteropod, a spider, or a group of any of these, dead 

 and decomposing; their organic juices, acids or alkalies have acted on the alkalies, acids 

 or metals in the silt sand, or ooze about them, and so formed layers of iron rust, or chrome, 

 clay or sand, which may have again changed and assumed the texture which we now 

 find. We have concretions which can be arranged in a series passing from most fantas- 

 tic forms through definite grades to those which are undoubted carpoliths, and as such 

 are figured by our best fossil botanists. 



The fossil remains of the Dacotah sandstones but rarely illustrate the fauna of that 

 age. In two localities, over limited areas, marine shells of some score species have been 

 found, and at one place, in Ellsworth county, we have a bivalve, probably estuarial, 

 among the mass of leaves. From a well near Delphos, in < )ttawa county, we have a 

 mass of pyrites containing casts, both internal and external, of gomatites. Another 

 compact arenaceous mass seems to be a saurian scapula ; and the books tell of another 

 saurian, from the clay near Brookville. 



But if there be paucity of faunal remains in the Dacotah, there is no scarcity of the 

 flora. The leaves are simply innumerable, and represent hundreds of species of plants, 

 from the humble weed to the lofty tree. Fruits, clearly determinable as such, are how- 

 ever rare, and twigs, branches and trunks are rarer still. In the north of Dickinson 

 county, one well-defined trunk has been taken out in sections and carried off by different 

 collectors, and small branches are not scarce in that immediate locality. We have 

 thought that some of the silicified and calcified logs of the Benton formation are probably 

 Dacotah trees, suddenly killed at the end of the period. Fruits, certainly recognized, 

 are those of juglans, prunes, and some other unnamed carpoliths. 



The leaves described and figured in Lesquereux's "Cretacous Flora" belong to 130 

 species, while his new volume will have 17 additional plates of new species, and other 

 species have been discovered this year. It is these leaves that have made the Dacotah 

 famous. They are the earliest dicotyledons. Eighteen years ago Prof. Swallow, in 

 the absence of fossils, ranked these sandstones as older than the Cretaceous system. 

 When the geologists of the National Survey found the fossil leaves in Nebraska, Prof. 

 Marcon pronounced the formation to be Tertiary. Now, certainly known to be Creta- 

 teous, it is famous for the leaf forms distinctly allied to, and some identical with, modern 

 species. Among the more conspicuous genera are Salix, Quercus, Magnolia, Sassafras, 

 Juglans, Laurus, Ficus, Fagus, Liquidambar, Sequoia, etc., etc. As in our modern forests, 

 the trees grew in groups, willow predominating in one locality, sassafras in another, and 

 so forth. Lesquereux noticed this fact more than ten years ago. The leaves are dis- 

 tributed throughout almost the entire vertical extent of the Dacotah formation. They 

 are found in the bottom sandstones and the shales beneath, as well as in all but the 

 highest arenaceous beds of the series, where they are scarce, if not absolutely lacking. 

 This is a vertical distribution of over 400 feet. It follows from this, that the forests, 

 which supplied these masses of leaves, flourished through the period necessary for the depo- 

 sition of over 400 feet of sandstone through the immense Dacotah area. If we go to a 

 modern seaside, where the tides are strong, we may notice the layer of sand deposited 



