490 PROCEEDINGS OF THE NEW YORK MEETING 



Logan particularly notes that, except on one side, the area of tlie terrace-flat 

 affected by the shp was bounded by lower land, a ridge or crest being left between 

 the collapsed area and this lower land. This is quite similar to the fact observed 

 in connection with llie landslip. on the Blanche, and is, no doubt, to be explained 

 in the manner previously alluded to. He nowhere saw the underlying rock or 

 other material below the clay, but is inclined to the belief tbat the movement 

 may have occurred on a sloping bed of rock. If, however, my interpretation of 

 the facts on the Blanche be correct, it seems unnecessary to assume the existence 

 of such a sliding surface in either case, the action of gravitation upon the saturated 

 mass of clay itself being probably sufficient to account for its flow to the lower 

 level, the retaining bank having been broken through in the first instance. 



The fifth paper of the morning session was : 



RIPPLE-MARKS AND CROSS-BEDDING 

 BY G. K. GILBERT 



Remarl?:s were made by the President, B. K. Emerson, A. C. Spencer, 

 C. W. Hayes, and the autlior. The paper is printed as pages 135-140 of 

 this volume. 



The sixth and closing paper of the session was upon 



VOLCANOES OF SOUTHEASTERN RUSSIA 

 BY H. FIELDING REID 



Doctor Reid's paper was discussed by E. O. Hovey, J. Stanley-Brown, 

 Angelo Heilprin, L. V. Pirsson, I. C. Russell, C. D. Walcott, and tlie 

 author. A short abstract is printed in Science, vokime 9, Januai:}'- 27, 

 1899, page 139. . 



The Secretary made some announcements regarding the order of papers 

 in the program. It was voted to organize for the afternoon session a 

 petrographic section, before which the papers on petrology and min- 

 eralogy should be read. The proceedings of this section will be found on 

 page 499. 



The Society adjourned for lunch, and reconvened at 1.30 o'clock p m. 



The first paper of the afternoon' session in the general section was read 

 by title. 



FORMATION OF DIKES AND VEINS 

 BY N. S. SHALKR 



The paper is printed as pages 253-262 of this volume. 



