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CONTENTS OF VOLUME XXYII 



Page 



Title page , i 



Contents iii 



Dates of publication and editions of the brochures ili 



List of illustrations iv 



Some Remarks upon Matthew's "Climate and Evolution." By T. Barbour. 



With Supplementary Note by W. D. Matthew 1 



An Extinct Octodont from the Island of Porto Rico, West Indies. By J. A. 



Allen. (Plates I-V) IT 



New Sirenian from the Tertiary of Porto Rico, West Indies. By W. D. 



Matthew . .- 23 



Theories of the Origin of Birds. By Willl4.m K. Gregory 31 



A Study of the Morrison Formation. By C. C. Mook. (Plate VI) 39- 



Preliminary Report of Fossil Mammals from Porto Rico, with descriptions 



of a new genus of ground sloth and two new genera of hystricomorph 



rodents. By H. E. Anthony. (Plates VII-XIV) 193 



Physiography of the Skykomisli Basin, Washington. By Warren S. 



Smith 205 



Operating Features of the Audion. By E. H. Armstrong 215 



Records of Meetings, 1916. By R. W. Tower 245 



Membership Lists, 31 December, 1916 315 



Index 329 



DATES OF PUBLICATION AND EDITIONS OF THE BROCHURES 



Pp. 1-15, 25 January, 1916 

 Pp. 17-22, 25 January, 1916 

 Pp. 23-29, 28 January, 1916 

 Pp. 31-38, 4 May, 1916 

 Pp. 39-191, 12 June, 1916 

 Pp. 193-203, 9 August, 1916 

 Pp. 205-214, 31 January, 1917 

 Pp. 215-243, 2 August, 1917 

 Pp. 245-336, 30 November, 1917 



Edition 

 1175 copies 

 1100 copies 

 1175 copies 

 1050 copies 

 1050 copies 

 1100 copies 

 1500 copies 

 1500 copies 

 1500 copies 



