54 Cincinnati Society of Natural History. 



that the land upon which the trees grew, was not very distant, and 

 by following the outcrops of the shale westward; in Highland 

 County, we find it thinning and coming to an edge on the shore of 

 what was evidently a land area which once extended from Cham- 

 paign County, southward, to Central Kentucky. 



Some years since I sent specimens of these silicified trunks to 

 Sir William Dawson, of Montreal, who was then giving special 

 attention to the Devonian flora, and had described f rom microscopic 

 examination several kinds of Devonian coniferous woods. He 

 pronounced the wood from the Huron shale to be a species of 

 Dadoxylon, new to science, to which he was kind enough to attach 

 my name. A short description of this was subsequently published 

 in the Transactions of the Royal Society of England, from which I 

 quote the following: 



" Dadoxylon Newberryi, Dawson. Cells of smaller diameter 

 than in D. Ouangondianum; areoles in two and three rows, not 

 quite contiguous ; central pore oval, oblique ; medullary rays very 

 numerous and unequal, cells in one or two series, and sometimes as 

 many as eighteen series of cells superimposed.'' 



The specimens on which the above description was based were 

 somewhat imperfect, the wood having been partially decayed 

 before silification. In order to secure a more complete description 

 I have recently given specimens of this fossil wood to my friend, 

 P. H. Dudley, of New York, and he has kindly returned to me the 

 following notes upon them : 



"The specimens of silicified wood from the Huron shale, which 

 you submitted to me for examination, present under the microscope 

 the following characters." 



Transverse Section. — Wood cells principally quadrangular, largest 

 diameter four to five hundredths of a mm.; thickness of cell walls, 

 one hundredth of a mm., and very uniform for the entire layers of 

 growth which are wide, limits not conspicuous ; medullary rays in 

 longitudinal sections very abundant. 



Radial Section. — The length of the cells of the medullary ray 

 four to five times their diameter, cell walls oblique; areolation of 

 cell walls in distinct groups, each group consisting of one, two or 

 three longitudinal rows of areoles, the pores of which are elliptical 

 and obliquely inclined; each areole is about one hundredth of a mm. 

 in diameter ; the groups of areola in the different cells are in radial 

 rows; the cell wall between each group is often slightly contracted. 



