138 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



invasion of 1874, as given in bis seventh annual reprot. With the 

 exception of a single county, visited in 1877, the migrations have not 

 extended east of the line as marked o'l his map in that report. 



We will now give a list of points along the eastern limit to which we 

 have positive knowledge that the migrations of the locusts have extended ; 

 a few points further east have been mentioned as among those visited, 

 but the testimony in reference to them is too doubtful and uncertain to 

 be used in fixing this eastern line. In connection with the points men- 

 tioned, the authority from whom the information has been obtained is. 

 given in all cases, except where the facts have been ascertained by the 

 Commission since its organization. Where limits previously fixed were 

 reached by swarms in 1877, we have relied upon our own data; hence in 

 such cases no authority is mentioned. This arrangement will enable the 

 reader to note the points along this line which the Commission has been 

 able to determine from observations made in 1877. It will also enable 

 him to mark the eastern range of flights for that year. 



British America. — According to Prof. G. M. Dawson, movements 

 toward the northeast have extended to the southern end of Lake Winni- 

 peg. From the reports received and recorded by him it is quite probable 

 that their migrations at this northern extremity of the visited area have 

 extended as far east as the 98th meridian. He also records their appear- 

 ance in 1875 at "Northwest Angle," Lake of the Woods. The swarm 

 seen passing this point moved onward toward the southeast. 



Minnesota and Wisconsin. — From the Lake of the Woods southward 

 to the line of the ^Northern Pacific Eailroad, with the exception of Indian 

 villages on the reservations, there are no settlements, consequently no 

 data from this area have been received, except some verbal reports that 

 swarms of grasshoppers have been seen (no date given) at Red Lake and 

 Leech Lake stations. From the latter point southward the line through 

 these States is represented by the following counties: Cass, Aitkin (Thom- 

 as, observation in person in 1872), Benton, and Sherburne, Anoka 

 (1856-'57 Walsh), Ramsey, Dakota, Pierce (Wisconsin), Dodge, and the 

 extreme southea.^t corner of Mower. 



Iowa. — The following counties in Iowa indicate the eastern limits 

 of the migrations in that State : Eastern line of Mitchell, Floyd, Butler, 

 and Grundy ; Tauia and Poweshiek; Warren and Clark (1867, Walsh); 

 and Taylor. A flight over Appanoose County in 1876 is reported, but 

 this is very doubtful. Mr. Walsh also mentions reported flights in the 

 neighborhood of Dubuque, but the evidence is not entirely satisfactory 

 in reference to the flights or the species. It is possible that now and 

 then a light swarm may be driven beyond what is the usual limit, but 

 we are not tracing these at present, our object in this chapter being to 

 fix as accurately as possible the true limits of their geographical distri- 

 bution. 



Missouri. — The following counties along the eastern limit of their move- 

 ments in Missouri were visited in 1877 : Polk, Dade, Lawrence, and 



