Geology and Mineralogy. 147 



concludes from his experiments — as many physicists may have 

 concluded from the published account of the supposed new force — 

 " that all the phenomena noticed by Mr. Edison are explainable 

 by the presence of inverse electrical currents of considerable 

 quantity, but comparatively small intensity, instantaneously pro- • 

 duced at the making or breaking of the battery circuit." 



II. G-EOLOGY A^D MINERALOGY. 



1. U. 8. Geological and Geographical Survey of the Territories, 

 F. V. Hatden in charge. Department of the Interior. Bulletin 

 No. 5, Second series. Washington, Jan. 6, 1876.— This new 

 Bulletin contains the following important papers : A review of 

 the fossil flora of North America, by L. Lesquereux; New fossil 

 plants of the Lignitic formations, and from the Dakota group of 

 the Cretaceous, by L. Lesqueeetjx ; Notes on the Lignitic group of 

 Eastern Colorado and Wyoming, by F. V. IIayden; Geology of 

 localities near Canon city, by S. G. Williams; On Zapiu " ^ 

 sonim, and on the breeding habit " 



. le white-tailed Ptarmiga 

 S. A. ; List of Hemiptera of the ^ 

 including those collected during the" explorations of 1873, by P.' 

 R. L'hler ; On the supposed ancient outlet of Great Salt Lake, 

 by A. S. Packard, Jr. 



The question as to the age of the Lignitic beds is here dis- 

 cussed anew by Prof. Lesquereux with the presentation of some 

 additional facts. His conclusions remain unchanged. They are 

 as follows.— Above the Lower Cretaceous beds or those of the 

 Dakota group, in the Rocky Mountain region, the first fossil 

 plants met with are the species of the Lignitic formation. This 

 formation is divided into (1) the Lower Lignitic, marked by the 

 presence of a profusion of Palms, especially species of Sabal 

 (showing a warm, moist climate, like that of Florida, while the 

 Cretaceous plants of the Dakota group indicate one like the 

 f Ohio) along with species of Fieus, Citinamomum, Mag- 



the Ev! 



) Acer), and referable to the Locene; (2) 



106^° W.) "or Middle Jliocene," aoove wnicn comes ^-4; tue 

 Oreen River Group, or Upper Miocene. The flora of No. 2 in- 

 cludes thus far 90 species, of which a third are known from No. 1 : 

 fruits have been found that have been referred to the Palms, but 

 no leaves ; there are also in it dentate and serrate leaves of Salix, 

 Aetata, Alniis and Acer. The flora of the Carbon Group is 

 "positively Miocene;" 18 species, or nearly a third of all, are 

 identical \vith European Miocene plants, and 1:J with Arctic Mio- 

 cene, while a few occur also in the Lower Lignitic (No. 1.) 



Among 23 species from the Point of Rocks, referred to No. 1, 

 or the Lower Lignitic, two occur also in beds to the north of the 



