32 FIRST ANNUAL REPORT OF 



of York, alone: the northeastern margin of which there is a mountain 

 range, sloping down to the river. Along that slope Cicadas were abun- 

 dant the present season (1S6S— Brood XXII). But on the southwest 

 side of the range, in what is known as the Kreitz Creek Valley, there 

 were none. They appeared last in this valley in 1853, and previous to 

 that year at intervals of seventeen years from time immemorial." 

 Dr. Smith records their appearance in 1853, both in Vinton county, 

 Ohio, and Jo. Daviess county, Illinois. 



BROOD IV.— Tredecim— 1857, 1870. 



In the year 1870, being the same as the preceding, they will in 

 all probability appear in Jackson, Gadsden and Washington counties, 

 Florida, having appeared there according to Dr. Smith in 184iand 57. 



BROOD V.—Scptemdccim—lS5i, 1871. 



In the year 1871, and at intervals of 17 years thereafter, they will 

 in all probability appear around the head of Lake Michigan, extend- 

 ing as far east as the middle of the State of Michigan, and west an 

 unknown distance into Iowa. Also in Walworth county and other por- 

 tions of Southern Wisconsin, and southward into Illinois. This brood 

 is equal to Dr. Fitch's 6th. It extends all over Northern Illinois, and 

 as far south as Edgar county, and its appearance in 1837 and 1S54 is 

 well and thoroughly recorded. In Champaign county, Ills., it over- 

 laps Brood XVIII, or the Southern Illinois tredecim brood, while it 

 also interlocks with Brood XIII (septemdecim) in the same county. 



They will also appear in the same years in the southeast by eastern 

 part of Lancaster county, Pa., in what is called the " Pequea Valley," 

 having appeared there in vast numbers in 1854. 



The earliest known record we have of the appearance of period- 

 cal Cicadas, is in Morton's "Memorial," in which it is stated that they 

 appeared at Plymouth, Plymouth county, Mass., in the year 1G33. — 

 Now, according to that date, one might be led to suppose that this re- 

 corded brood of Morton's belonged to this Brood III, as exactly 14 

 periods of 17 years will have elapsed between 1633 and 1871; but, 

 strange to say, we have no other records of his brood than that in the 

 "Memorial," whereas there are abundant records of their appearing 

 one year later in the same locality, ever since 1787. There is there- 

 fore good reason to believe that the visit recorded by Morton was a 

 premature one, and that it was properly due in 1634. I have there- 

 fore placed it in Brood XIII, and have little doubt but that if records 

 could be found, these would prove the Cicadas to have appeared in 

 1651, 1668, 1685, 1702, 1719, 1736, 1753, and 1770, as they did in 1787, 

 1804, 1821, 1838, and 1855. 



BROOD VI.— Tredecim— 1858, 1871. 



In the year 1871, being the same year as the preceding, and at in- 

 tervals of 13 years thereafter, they will in all probability appear in 



