12 
IOWA ACADEMY OF SCIENCE Vor,. XXVII, 1920 
Swimming Pool Sanitation. Jack J. Hinman 258 
Cladocera of the Okoboji Region. Frank A. Stromsten 265 
Copepoda of the Okoboji Region. Frank A. Stromsten 269 
Rotatoria of the Okoboji Region. Dwight C. Ensign 271 
Similarities Between the Lateral Line Systems, of Elasmobranchs and 
Amphibians. H. W. Norris 
Susceptible and Resistant Phases of the Dividing Sea-Urchin Egg 
When Subjected to Various Concentrations of Lipoidsoluble Sub- 
stances, Especially the Higher Alcohols. Francis Marsh Baldwin... 287 
Notes on the Branches of the Aorta (Arcus Aortae) and the Sub- 
clavian Artery of the Rabbit. Francis Marsh Baldwin 301 
The Relative Position of the Maxima Contractions of the Amphibian 
Muscle When Subjected to Various Ranges in Temperature. Ralph 
L. Parker 311 
A Revision of the Cercopidae of North America North of Mexico. 
E. D. Ball 
Some Iowa Records of Lepidoptera. A. W. Lindsey 319 
A Study of the Phylogeny of the Anteoninae. F. A. Fenton 337 
On the Parasites of the Unios of the Lake Okoboji Region. Harry M. 
Kelly 
A Review of the Desert Leafhoppers of the Orgerini (Rhynchota Ful- 
goridae), E. D. Ball and Albert Hartzell 
The Pathology of Lethargic Encephalitis. Henrietta Calhoun 
Notes on Some Dipterous Parasites of Leaf hoppers, I. L. Ressler 
Recent Outbreaks of Army Worms and Variegated Cutworms in 
Iowa. H. E. Jaques 343 
A Biological Reconnaissance of Okefinokee Swamp, Georgia: The 
Fishes. E. Laurence Palmer and A. H. Wright 353 
Bird Records of the Season 1919-1920 in the Vicinity of Iowa City. 
Dayton Stoner 379 
An Intensive Ornithological Survey of a Typical Square Mile of Cul- 
tivated Prairie. Arthur R. Abel 385 
Bird Records of the Past Two Winters, 1918-1920, in the Upper Mis- 
souri Valley. T. C. Stephens ' 395 
Archeology 
The Material for a Study of Iowa Archeology. Charles Reuben Keyes 
The Keokuk Type of Stone Ax. Charles Reuben Keyes 
