﻿Geology and Natural History. 77 



II. Geology axd Natural History. 



1. The Cretaceous Flora of North America. — An abstract of 

 a paper by Professor Newbeeey on the Cretaceous Flora of 

 North America, in the Trans. N. Y. Acacl. Sci., No. 5, 1886, 

 mentions the discovery of great numbers of leaves of Angiosperms 

 in the Raritan or Amboy clays of the New Jersey Cretaceous, 

 and states that the author has already fifty quarto plates of draw- 

 ings ready for the engraver. The clays are largely explored for 

 making brick and pottery. Professor Newberry regards the clays 

 as the equivalent of the western Dakota group, the Atane beds 

 of California, and of the Upper Greensand of England. The 

 Angiospermous leaves, of which there are fifty to sixty species, 

 pertain to the genera Liriodendron, Magnolia, Sassafras, Aralia, 

 Celastrus, Gelastrophyllum, Scdix, and what Heer has called 

 Hedera, Ficus, Diospyros, Juglans and others. With these, many 

 specimens have been found ot a helianthoid species of the Com- 

 posite, having a flower three to four inches in diameter, in which 

 the ray florets (?) were scarious and persistent like those of Heli- 

 ochrysum. 



There are also fine species of two genera of Leguminosa?, 

 Bauhinia and Hymaanea, not before reported from the North 

 American Cretaceous. The specimens gathered include also 

 about a dozen species of Conifers, as many Ferns, and two or 

 three Cycads. " Taken together," says Professor Newberry, 

 "this flora is of surprisingly high botanical rank, quite as much 

 so as that obtained from any Tertiary strata." The Mill Creek 

 beds of British America are referred by him to the same horizon ; 

 and the Peace River are made the equivalent of the Chalk. 



From the Potomac clays of Virginia, a still older Cretaceous 

 flora, supposed to be Neocomian, has been found by Professor 

 Fontaine, # where " a large number of species of Cycads, Coni- 

 fers and Ferns occur along with a few Angiosperms." The 

 plants of beds of the Queen Charlotte Islands are referred to the 

 same horizon. 



2. Periods of enlargement and diminution in the Glaciers of 

 the Alps. — Mr. Fokel reports, from the data which he has collected 

 with much care, that there have been this century five periods in 

 the Alpine glaciers ; of enlargement from 1800 (?) to 1815 ; of dim- 

 inution from 1815 to 1830 ; of enlargement from 1830 to 1845 ; of 

 diminution from 1845 to 1875 ; and of enlargement again from 1875 

 onward. He remarks further that these periods correspond with 

 those deduced by Mr. C. Lang for the variations in precipitation 

 and temperature of the air ; and consequently, that the enlarge- 

 ment of the glaciers has gone forward in the cold and rainy pe- 

 riod and the diminution in the warm and dry. — Archives Sci. 

 Fhys. Nat., May 15, 1886, p. 503. 



3. Maps pxujlished by the U. S. Geological Survey. — The Geo- 

 logical Survey, in carrying forward the preparation of a geologi- 



