-^Vl^; 



CONTENTS. 



XXII — Ou the Origin of the Carbonaceous ]\[atter in Bituminous 



Shales. By John S. Newberry ^57 



XXIII — Description of Two Ncav Species of Zonitesfrom Tennessee. 



Bj^ Thomas Bland 868 



XXIIIft-Description of Two Species of Land Shells from Porto 



Rico, W. I. By Prof. Edavarp von Martens 370 



XXIV— An Apparatus for Rapid Gas Analyses. By Arthur H. 



Elliott, (with Plates XXII and XXIII) . /. 872 



XXV — Descriptions of New Species of Birds of the Genera 

 C'hrysotis, Formicivora and Spermophila. By George N. 

 Lawrence 381 



XXVI— Observations of the Transit of Venus, December, 1882. By 



John K. Reej^ 384 



'b'. _ . _ ftP 



746 





'vd t 



