510 THE AMERICAN NATURALIST. 
the plant-bearing series of that region with the Coal Measures in 
other parts of the United States. In all, sixty-nine forms or species 
are represented. The types of Mariopteris, Neuropteris, and Pecop- 
teris are especially abundant and prominent, while the relatively 
small percentages of species common to the two stages show that 
there are marked differences between the floral characters of the 
three stages represented in the McAlister coal field. 
Recent studies by David White (Bul. Geol. Soc. Amer., Vol. II, 
p. 145) present an interesting discussion of the relative ages of the 
Kanawha and Allegheny series, and afford an excellent illustration 
of the value of correctly interpreted paleobotanical data in deter- 
mining the age of deposits. 
The latest contribution to our knowledge of that remarkable 
collection of Mesozoic cycads now to be found in the Yale Museum 
is from the pen of Professor L. F. Ward (Amer. Journ. Sa, VOL X, 
p. 327), who details the history of the 731 specimens there brought 
together, and adds to his previous lists descriptions of seven new 
species embraced in hitherto unclassified material. 
D F F: 
