CHRONOLOGICAL ACCOUNT OF D1FFEEENT BROOD 2 1 
the Wisconsin River to its mouth. There seeine also to be a detached 
branch commencing about the middle of the northern part of Iowa 
County and running across the Wisconsin River into Sank County. In- 
cidentally with his studies on Brood XIII, Prof. 0. E. Bessey, of Ames, 
Iowa, was able in 1 <S 7 8 to define the boundary of this Brood V of 
1871, and to illustrate its extent in his State by a map published in the 
Iowa Weather Bulletin for November, 1878. The brood occupies nearly 
the whole eastern third of the State, not reaching, however, the south- 
eastern corner and being limited toward the west by a line drawn from 
Mitchell County to a point on the Mississippi River somewhat south of 
the mouth of the Iowa River. In its southeastern portion this brood 
overlaps, therefore, Brood XIII. In Illinois the boundary line, in a gen- 
eral way, maybe drawn from the northwest portion of Mercer County, 
southeast to the Illinois River at Peoria, west along the Toledo. Wabash 
and Western Railroad. There seem to be detachments extending far- 
ther south, especially in the eastern portion of the State, and they oc- 
curred as far south as Shelby County. In Indiana the line is not well 
defined, but includes the extreme northwest counties, extending as far 
south as the Kankakee River. In Michigan it does not extend north as 
far as Saint Joseph on Lake Michigan. 
As this insect can only appear in districts which were timbered or 
planted to orchard seventeen years ago, it follows that in such an ex- 
tensive prairie country as that within the limits indicated, the brood 
must be very much detached and scattered. 
The insects did not appear in the Pequea Valley, in Lancaster County, 
Pennsylvania; at least I have been unable to get any authentic record 
of the fact. 
From all I can learn, no Cicadas appeared at Plymouth, Mass., a fact 
which corroborates the view expressed in L868, that the visit recorded 
by Morton in 1633 was a premature one, and that it was due in 1634. 
The southern boundary of this brood in Illinois needs further defi- 
nition. Mr. A. C. Hammond, of Warsaw. Hancock County, wrote me 
that in 1871 it did not occur at Warsaw, and the same statement was 
made to me by Mr. M. L. Dunlap in regard to the vicinity of Cham- 
paign. 
Mr. S. S. Rathvon, of Lancaster. Pa., subsequently (May 17. 1 
informed me by letter that he had also tailed in 1871 to hear anything 
of this brood in Pennsylvania. 
Belated individuals of this brood were reported to me by Air. B. S, L. 
Richardson, from Oswego, Kendall County, Illinois, on June 20, 1872, 
who also states at the same time that the Cicadas were there in ' 
18o4, and 1.S71. 
Brood VI.— Tredecini— 1884, IH97. 
In The year 1871, being the sainc year as the preceding, ami a i intervals ft' thirteen 
year- thereafter, they will, in all probability, appear in the extreme southwestern 
