100 



SCIENCE. 



[N. S. Vol. XI. No. 264. 



of other observers and the Indian legends. 

 He showed the general topography and 

 geology by means of maps, and explained 

 his estimate of the lapse of time by the 

 rings in the stumps of trees which had 

 grown on the landslide. There is also a 

 river terrace about 100 feet above the 

 present water level. The landslide there- 

 fore ponded the river and drowned the 

 trees standing above it. In discussion J. 

 A. Holmes cited cypress trees, in good 

 preservation, 20 feet below the bottoms of 

 rivers in North Carolina, and Gr. B. Shat- 

 tuck spoke of similar cases in Maryland in 

 the Pleistocene. 



Fhysiographic development of the Washington 



region. By K. H. Darton, Washington, 



D. C. 



A general sketch was presented, illus- 

 trated by maps and photographic illustra- 

 tions, and intended to give visiting geolo- 

 gists an outline of the principal features of 

 the Mesozoic to recent geology. 



The paper was not meant for publica- 

 tion, but it served to set before the Society 

 an excellent idea of the geological for- 

 mations near Washington and their physi- 

 ographic development. 



Erosion forms in the Harney Peak District, 



Black Hills, South Dakota. By Edmund 



Otis Hovet, ISTew York City. 



The paper consisted of the exhibition of 

 about ten lantern slides, showing the pe- 

 culiar forms produced by erosion in the 

 schists and pegmatites in the Harney Peak 

 District in the Black Hills of South Dakota. 



The slides illustrated the curiously 

 sheeted and jointed granite which leads to 

 the production of very rough topography. 

 Pictures of the large spodumene crystals 

 at the Harney Peak tin mines were also 

 thrown upon the screen. 



In discussion President Emerson com- 

 pared the spodumenes with those of Massa- 

 chusetts. S. F. Emmons described the oc- 



currence of the spodumenes in pegmatites. 

 I. C. Russell inquired if there were evi- 

 dences of glaciation in the hills ; Mr. Hovey 

 replied, no. A. C. Spencer inquired if the 

 Sylvan Lake was a rock -basin. This was 

 likewise answered in the negative. 



Tojjographie features of Ohio. By W. Gr. 



Tight, Granville, O. 



The general topographic features of the 

 different sections of the State were discussed 

 and an attempt was made to show the 

 reasons for the different tj-^pes. The paper 

 was illustrated with lantern views. 



The author remarked the paucity of in- 

 formation about the physiography of the 

 State in general. He divided it into three 

 areas : the northwestern, within the limits of 

 the glacial ice ; the border, a belt along the 

 terminal moraine; and the southeastern, 

 outside the drift. The readjustments of 

 drainage and the various topographic forms 

 were admirably illustrated. In discussion 

 M. E. Campbell inquired if there was good 

 evidence of peneplains in the southeast ; the 

 author replied that there was some but that 

 it was not conclusive. I. C. White dis- 

 cussed the general directionsof the drainage. 



Drainage modifications in Southeastern Ohio. 



By W. G. Tight, Granville, Ohio. 



The changes in drainage of the region 

 north of the Ohio river and between the 

 lower Muskingum and the lower Scioto 

 have been very great. The lower Muskin- 

 gum, south of Zanesville, is shown to be a 

 composite stream made up of sections of 

 four preglacial streams which crossed the 

 course of the present Muskingum. These 

 four streams united in what is now the 

 Little Hocking basin, and the main line of 

 preglacial drainage extended across the 

 present Hocking river, which is also shown 

 to be composed of sections of several pre- 

 glacial streams, into the basin of Eaccoon 

 creek and across this basin into that of the 

 Scioto river below Chillicothe. Several of 



