PROCEEDINGS. 
531 
331st Meeting. February 16, 1889. 
President Eastman in the chair. 
Thirty-three members present. 
The Chair announced the election to membership of Messrs. 
Cosmos Mindeleff and Victor Mindeleff. 
Mr. C. 0. Boutelle read an obituary notice of Mr. H. F. 
Walling, published in full in this volume, pp. 466-470. 
Mr. I. C. Russell made a communication on Sub-Aerial De¬ 
posits of the Arid Region of North America, published in full 
in the Geological Magazine, 8vo, London, 1889, July and August, 
vol. 6, No. 7, pp. 289-295; No. 8, pp. 342-350. 
Mr. Swan M. Burnett made a communication entitled Ex¬ 
hibition of Models Showing Refraction by Cylinders with their 
Axes Crossed at Various Angles. 
332d Meeting. March 2, 1889. 
President Eastman in the chair. 
Forty-eight members and guests present. 
Mr. H. V. Wurdeman read a paper on Color Perception. 
Mr. S. P. Langley read a paper on the Observation of Sudden 
Phenomena. 
Published in full in this volume, pp. 41-50; also in: American 
Journal of Science, 8vo, New Haven, 1889, August, vol. 38, 
No. 224, pp. 93-100. 
333d Meeting. March 16, 1889. 
President Eastman in the chair. 
Twenty-seven members and guests present. 
The Chair announced the election to membership of Mr. John 
George Hagen. 
Mr. J. S. Diller made a communication on The History of 
Porphyritic Quartz in Eruptive Rocks. 
