DISTRTBFTIOX — SOURCES OF INFORMATION 
25 
The older authors, such as Harris and Potter, gave no catalogue 
other than a list of the Cicada years and localities. 
A number of maps have been prepared, and are introduced as text 
figures illustrating (1) the general range of the 13-year broods. (2 the 
range of the 17-year broods, and (3) a series of 1 * i year maps illustrat- 
ing the distribution of the different broods daring the next sixteen 
years, beginning with the year 189S. 
The preparation of these maps and the careful listing of the distribu- 
tion of the broods by States and counties is largely the work of .Mr. 
B. S. Clifton of this office. 
THE GENERAL RANGE OF THE SPECIES AND OF THE TWO RACES. 
Taking all the different broods together, this Cicada is known to 
occur pretty generally within the limits of the United States east of the 
Fio. 2.— Map showing distribution of the broods of the 13-year race. 
Rocky Mountains. No broods have been found in northern New Eng- 
land, northern Michigan, nor in Minnesota; or. in other words, it does 
not seem to occur in sections in which the forest growth is almost exclu- 
sively pines or other conifers. In the Stale of Rhode Island then 
no positive records of the occurrence of this insect, but since it occurs 
in Connecticut and also near Fall River and on Marthas Vineyard 
in Massachusetts, this may be simply from lack of observation or the 
fact that the specimens are few in number and not likely to be noted. 
In the South it is not known in the peninsula of Florida, although it 
occurs iu the northwestern counties o\' the State, but its absence here 
