V. Housing in Relation to Health, Dean Marion Talbot, 
University of Chicago 62 
Individual Papers: 
A Celestial Sphere in a Natural History Museum, W. W. 
Atwood 66 
Annotated List of the Algae of Eastern Illinois, E. N. Tran- 
seau 69 
The Sexton Creek Limestone in Illinois, T. E. Savage .... 90 
A New Species of Marionina from Illinois, F. Smith and P. 
S. Welsh 90 
A Black-Crowned Night Heronry and Need of its Protec- 
tion, C. W. Finley 90 
Reproduction by Layering in the Black Spruce, George D. 
Fuller 91 
Evaporation and Soil Moisture on the Prairies of Illinois, 
E. M. Harvey 92 
The Stratification of Atmospheric Humidity in the For- 
est, G. D. Fuller, J. R. Locke and Wade McNutt 100 
Distribution of the Fish in the Streams about Charleston, 
Illinois, T. L. Hankinson 102 
The Disappearing Beaver, Elliot R. Downing 113 
Practical Cloud Studies, M. L. Fuller 115 
The Stratigraphy of the Chester Group in Southern Illinois, 
Stuart Weller 118 
List of Members 130 
