March 13, 1908] 



SCIENCE 



411 



charactei'istic Knoxville fauna, and on the 

 other with a fauna that may be older than 

 the Mariposa. 



Local Silicification of the Knoxville: J. S. 



DiLLEB, Washington, D. C. 



There are certain localities in the Riddles 

 Quadrangle and the adjacent region of 

 Oregon in which portions of the Knoxville 

 strata axe silieified and contain numerous 

 small quartz veins. In these quartz- veined 

 rocks Ancella pioclii and Ancella crassi- 

 collis are widely but sparsely distributed. 

 When these fossils are abundant the cement 

 is calcareous and the rocks are less firmly 

 lithified. Discussed by A. C. Lawson. 



On account of the special interest due to 

 the excursion after the meeting to the 

 Grand Canyon of the Colorado, the follow- 

 ing paper was, in the absence of its author, 

 read by Dr. C. W. Hayes : 

 Wind Erosion in the Plateau Country: 



Whitman Cross, Washington, D. C. 



The next paper was read by title: 



The Association of Pegmatite with Rorn- 

 Mendic Border Beds of Granite and the 

 Appearance of Large Isolated Masses of 

 the Two together Deep in the Ground: 

 B. K. Emerson, Amherst, Mass. 

 The next paper was read by Mr. Louder- 

 back. It was 



Benitoite, its Mineralogy, Paragenesis and 



Geological Occurrence: George D. 



LouDERBACK and W. C. Blasdale, 



Berkeley, Cal. 



Benitoite and the associated minerals 

 were briefly described and chemical an- 

 alyses presented. The paragenesis and 

 geological mode of occurrence were dis- 

 cussed and compared with geologically 

 related but mineralogically different de- 

 posits in the same geologic province. Dis- 

 cussed by W. G. Tight. 



The next papers were read by title, as 

 follows : 



The Igneous Bocks of the Ortez Moun- 

 tains: Ida H. Ogilvie, New York, N. T. 



The Preglacial Drainage in Central West- 

 ern New York: Amadeus W. Geabau, 

 New York, N. Y. 



Geographic Cycle in an Arid Climate: 

 Charles R. Keyes, Des Moines, la. 



The next paper read was 



Shoreline Studies on Lake Ontario and 



Erie: Alfred W. G. Wilson, Montreal, 



Canada. 



The initial shore lines of these lakes were 

 very complex because of the complex char- 

 acter of the basins in which they lie. The 

 process by which the shore lines have been 

 brought to their present stage of develop- 

 ment is almost wholly due to the action of 

 waves and the currents generated by them. 

 Tides and other currents strong enough to 

 be effective agents in transportation do not 

 exist in the Great Lakes. The materials 

 found on the shores are almost wholly of 

 glacial origin. They are being distributed 

 along the shores by the shore processes, 

 and there is evidence of the existence of 

 two nodal points on each lake, one on the 

 north shore, and one on the south. East 

 of these points the resultant general move- 

 ment of shore debris is east, west of these 

 points it is west. Locally there may be at 

 any specified time movements in either 

 direction, according to the direction of 

 wind and wave at that time. 



Some special features of the shore lines 

 were described in detail— such as Toronto 

 Island on Lake Ontario, Long Point, Ron- 

 deau Point, Point Pelee and Erie Point, on 

 Lake Erie. 



The place of the shore lines in the cycle 

 of shore development was considered and 

 they were classed as adolescent. 



The following papers were then read by 

 title : 



