1888.] 517 [General Meeting. 



has been throughout, as now, a very quiet and gentle process. (4) 

 The hard pebbles and bowlders of quartzite, etc., now covering 

 the whole face of the country, are, except in the actual beds of the 

 streams, virtually proof against removal or disintegration under 

 existing conditions. In short, the quiet erosion of the soft clays, 

 muds and sands forming the Miocene and Upper Cretaceous beds 

 has left these indestructible pebbles and bowlders essentially in- 

 tact ; and as they are now, we may expect they will remain until 

 some future submergence hands them down to a later sedimentary 

 formation. The sufficiency of this explanation is further attested 

 by the fact that in the Bad Lands many of the hills and slopes are 

 thickly strewn, often to the depth of several inches, with angular 

 fragments of the chalcedony which forms thin veins traversing 

 the soft Tertiary beds. Even in the stream beds, these fragments 

 of chalcedony are usually but little rounded ; and we may fairly 

 suppose that the fragments which now encumber the surface repre- 

 sent a considerable thickness of clay and marl which has been 

 washed away, the chalcedony, like the rolled pebbles from the Mi- 

 ocene beach, remaining behind as an inert residuum. 



Professor Hyatt spoke of some features in the geology of Lake 

 Huron, confirming views expressed by Professor Crosby. 



The Curator showed a male and female Kiwi, wingless birds 

 from New Zealand, presented by Messrs. W. C. Pope & Co. of 

 Boston, to whom the thanks of the Society were unanimously voted 

 for this gift. 



General Meeting, March 21, 1888. 



The President, Prof. F. W. Putnam, in the chair. 



The following vote of the Council was read : — 



Voted: That the Council, having duly considered the correspon- 

 dence which has passed between a Committee of our own number 

 and the Park Commissioners just published, asks the Societj^ to 

 authorize the Council to take such steps as shall be necessaiy to 

 secure to the City of Boston a Natural History Garden and Aqua- 

 ria, which shall then be under the direction of the Society. 



