IOWA ACADEMY OF SCIENCES. 197 



The counties reporting Cicadas for 1888 are as follows: Ben- 

 ton, Black Hawk, Buchanan, Clayton, Clinton, Cedar, Delaware, 

 Dubuque, Iowa, Jackson, Johnson, Jones, Louisa, Muscatine, 

 Scott, Tama. This shows only the counties reporting but does 

 not indicate the extent or distribution in the counties, and this, 

 for th^ border counties particularly, is quite important in fix- 

 ing a definite boundary. I took pains therefore to locate the 

 particular township from which the reports came, which was 

 possible by examining the records at the secretary's of&ce in 

 Des Moines, and was thus able to locate the actual boundary 

 usually within six miles at most, certainly within the limits of 

 the ordinary flight of the insect. 



The line of townships beginning at the Mississippi river in 

 Muscatine county and naming those on the border line from 

 which positive reports were received is as follows: Muscatine 

 county, Fruitland, Cedar; Louisa county, Columbus City; Iowa 

 county, York, Summer; Benton county, Saint Clair; Tama 

 county, Clark, Geneseo; Black Hawk county, Spiny Creek; 

 Buchanan county, Sumner; Clayton county. Cox Creek, Clayton. 



For convenience sake we may carry our line through the 

 towns and villages nearest this line and it will be approxi- 

 mately as follows: Fruitland, along south line of Muscatine 

 to Columbus City, then along the west of the Iowa river till in 

 Johnson county, then northwest to York Center, Iowa county 

 and to near Ladora, then northeast to Blairstown, then north- 

 west to Dysart, then northeast through Laporte City, Independ- 

 ence, Strawberry Point, Elkaier and Clayton. 



The area of natural timber corresponding for the most part 

 with the valleys of the rivers and smaller streams, the distribu- 

 tion of Cicada may be pretty accurately expressed by defining 

 them, and on this basis they may be said to occur in the valley 

 of the Iowa river from Columbus City to west of Marengo, in 

 the valley of the Cedar river and its tributaries as far to the 

 northwest as Laporte City. In the Wapsipinicon to Independ- 

 ence, in the Maquoketa to Strawberry Point, in the Turkey 

 to Elkader, and north on the Mississippi from south central 

 Muscatine county nearly to McGregor. 



Numerous reports not specially indicated, attest their abun- 

 dance in all the central counties of this area and need not be 

 specified but some which bear particularly upon the border 

 line may be quoted here. 



