22 KANSAS ACADEMY OF SCIENCE. 



taceous areas. The. rocks above Junction City are decidedly Permian, yet in 

 little gullies among them we have found hard, siliceous ironstone pebbles 

 that tell of the Dakota strata, long since vanished. 



Some of the specimens of fossil wood are of siliceous limestone, with occa- 

 sionally the silica very small in quantity, and the specimen might almost be 

 described as hard chalk. This class has more numerous specimens than the 

 kind we should be inclined to attribute to the Dakota. Till recently we in- 

 clined to refer these to recent action of water percolating through Cretaceous 

 or Permian limestones, on recent wood imbedded in their creyices or in se:len- 

 tary soils. Two specimens found last August have led to a change of this 

 opinion. 



In a ravine leading northward to the Saline river, in Russell county, we 

 picked up one of these limestone petrifactions that had such a resemblance 

 to the Benton rocks around that it induced further search, which was re- 

 warded beyond possible anticipation. On a projecting ledge, and forming 

 part of a stratum above it that was considerably weathered, I observed some 

 impressions of shells. The piece of which they formed a part, though large, 

 easily broke off, and the under side was entirely petrified wood, the fibres and 

 cells being shown in both longitudinal and cross-sections as distinctly as in 

 the large Dakota tree of Dickinson county. Here was a piece of a log that 

 floated in the early Benton Sea, over the enormous Inocramus bed, and be- 

 coming weighty with water, dropped down among shells, and in the lapse of 

 ceons since has become like them, a part of the solid limestone. We know it 

 was the early Benton, because a little way further down the ravine we came 

 to an outcrop of the soft, light-colored sandstone which often forms the upper 

 horizon of the Dakota. 



The facts we have narrated are significant. We believe they all point one 

 way, viz., to the Cretaceous origin of most of the specimens of fossil wood 

 found on our prairies. They also point to the desirability of submitting a 

 series of these specimens to competent histological examination, so that by 

 comparison with modern wood tissue the genera, if not the species, might be 

 defined. It would be a beautiful result, but one that we should be led to 

 expect, if such investigation referred the fossil woods to species of platanus, 

 sassafras, quercus, salix and laurus, that have left their leaves impressed so 

 fairly and in such multitudes on the sands of the Dakota shores. 



