44 THE PERIODICAL CICADA. 
inhabitants of Lancaster, Pa., will also have the opportunity this year 
of listening to the music of the Cicadas within the limits of their city, 
as Mr. 8S. S. Rathvon saw them abundantly at that place in 1868. — 
The late I’. S. Sleeper, of Galesburg, Kalamazoo County, furnished 
me the following interesting statement regardipg the distribution of the 
Cicada in his county: ‘“ During 1868 they appeared in great numbers in 
this locality, being confined to a narrow strip about four miles in width 
through the northern part of this county. In this strip the ground was 
fairly honeycombed in appearance where they came up. There were 
some scattering ones out of this strip. My mother states that they were 
very abundant seventeen years previous (1851).” 
Regarding the extent of this brood in northwestern Ohio and the di- 
viding line between this and Brood XV, compare the letter of Mr. J. H. 
Niles, of Havana, Huron County, Ohio, which I quoted on p. 34. In 
the same letter Mr. Niles continues as follows: ‘*‘ Five miles west of this 
dividing line, in the northeast corner of Seneca County and the adjoin- 
ing corner of Sandusky County, is located the brood of 1885. They oc- 
cupy only some 350 square miles, and are ona cluster of ridges of the 
ancient lake coast deposit, overlaying the limestone soils.” 
This is the largest 17-year brood on record, and although it does not 
appear to reach the Mississippi River it certainly equals in extent the 
largest 13-year Brood XVIII, both broods having appeared simulta- 
neously in the year 1868. In the more northern States this Brood X XIT 
appears to be broken up in several isolated detachments, while its 
southern extension, viz., from North Carolina to northern Georgia, is 
not yet established as fully as might be desired. 
SUMMARY OF DISTBIBUTION AND FUTURE APPEARANCE. 
Summing up the distribution of the Periodical Cicada (both 17- and 
13-year races) within the United States, as specified in the above enu- 
meration of the different broods, it will be seen that the Cicada is known 
to occur in all the States east of the plains excepting the northern por- 
tion of New England, northern Michigan, and the whole of Minnesota. 
It thus appears that this Cicada does not breed in those northern States 
or portions thereof in which the woods are composed more or less ex- 
clusively of pine trees or other conifers. hode Island possesses no 
broods so far as we know, but this may be due to want of proper records, 
as several broods reach close to the borders of that State. Neither does 
the species occur in the peninsula of Florida, for reasons either of a 
climatic or geologic nature. Our knowledge of the western extent 
has greatly increased since 1868, and several broods can now be traced 
as far west as eastern Montana and Wyoming, central Colorado, and 
the extreme western parts of Texas, while less reliable evidence even 
indicates (vide Brood XX) that the species may occur in western Mon- 
tana along streams emptying into the Pacific Ocean. Unless this report 
