26 BULLETIN OF THE 



Mr. L. D. Gale made a communication 



ON THE FAILURE OF THE WOODEN PAVEMENTS OF WASHINGTON 



CITY : 



contrasting them with those of other cities, and attributing their 

 decay in great part to the practice of sprinliling the streets. He 

 also described a contrivance for protecting them, which he had 

 Invented. 



Mr. T. N. Gill made a communication 



ON THE GEOGRAPHICAL DISTRIBUTION OF MAMMALS: 



and elucidated doubtful points by reference to phenomena in 

 other classes of vertebrates. His conclusions were that at re- 

 mote periods Australia, South America, .and Africa had been 

 colonized from a common source, and hence might be grouped 

 into a division — Eogaea — contrasted with anothei* — Pleiogaea — 

 containing other regions. Of these Australia retains the greater 

 number of primitive features, as illustrated by Paleontology ; 

 and Africa has received the greatest number of intrusive ele- 

 ments. 



Considerable discussion followed, in which the President and 

 Messrs. Meigs, Welling, and Taylor participated, 



80th Meeting. January 16, 1875. 



Vice-President Taylor in the Chair. 



Forty members and visitors present. 



The Chair announced the election of Dr. A. F. A. King, Dr.EMiL 

 Bessels, and Mr. Joseph Wood as members of the Society. 



Mr. C. B. Button read a paper 



ON THE glacial PERIOD : 



giving an historical account of the progress of speculation and 

 investigation, and the more recent theories respecting such a 

 period, and showing the slight basis on which they rested, and 

 stating some facts and considerations opposed to them. He 

 also referred to a recent article by Mr. Sclater on the geographi- 

 cal distribution of animals. 



