of so small extent that no relationship between the two broods can 

 be pointed out. Comparisons with other 17-year broods are very 

 tempting but are of course mere speculation in the present state of 

 our knowledge. Still, can it be a mere coincidence that the territory 

 occupied by Brood XX (1883-1000) is evidently a northeastward 

 extension of that occupied by Brood XV ; or are geological reasons 

 sufficient to explain the fact that the territory occupied by Brood XV 

 almost exactly fills the gap between the two great divisions of Brood 

 XXII (1885-1902) V 



The localities from which Brood XV has been recorded are as 

 follows : 



Pennsylvania : — Counties of Fayette and Washington. 



West Virginia: — Counties of Barbour, Calhoun, Kanawha, 

 Grant, Hardy, Harrison, Lewis, Marion, Monongalia, Ohio, Pres- 

 ton, Roane, Tucker. 



Virginia : — County of Highland (?) 



Ohio: — Counties of Belmont, Coshocton, Crawford, Erie, Fairfield, 

 Geauga, Guernsey, Huron, Jackson, Lake, Licking, Muskingum, 

 Perry, Pickaway, Washington. 



THIRTEEN-YEAR BROOD VI — 1884-1897-1910. 



The 13-year Brood XV which appeared in 1897 is of small extent, 

 but well established by many reliable records, the oldest of which 

 dates back as far as 1806. It is confined to parts of southern 

 Mississippi and adjacent parts of Louisiana east of the Mississippi, 

 the particular localities being given farther on. Dr. D. L. Phares, 

 of Woodville, Miss., has taken particular pains to ascertain the ex- 

 tent of this brood and his lucid and concise account already pub- 

 lished in 1885 in Bulletin 8 (first series) of this Division, is herewith 

 reproduced : 



This western limit is the Mississippi River ; the southern about 8 miles north 

 of Baton Rouge ; the eastern about 4 miles west of Greensburg, the county seat 

 of Helena, and 4 miles west also of Liberty, in Amite County, Miss., thus 

 extending from 15 to 50 miles from the Mississippi River, and from the vicinity 

 of Baton Rouge, 108 miles to the northern limit of Claiborne County, Miss., 

 perhaps even farther. They, therefore, occupy East and West Feliciana, the 

 northern part of East Baton Rouge, the northwest corner of Livingston and 

 the western part of St. Helena parishes, Louisiana ; and Wilkinson, Adams, Jef- 

 ferson, Claiborne, and parts of Amite, Franklin, and possibly parts of one or two 

 more counties in Mississippi. 



The reports received since 1885 are mostly confirmatory of Dr. 

 Phares's statement, but Mr. Thos. F. Anderson, of St. Helena, La., 

 writes us that the parishes, or at least parts of the parishes of Tan- 

 gipahoa, Washington, and St. Tammany had to be added to the 

 range of this brood. His statement is quite definite; still a confirm- 

 ation of these new localities is desirable. 



