THE AMERICAN ENTOMOLOGIST. 



29 



probably they were drowned. (3) In 



1861 according to old settlers. [C.E.B.] 



Boon. A correspondent informs me that 



they were in this county this year. 

 Greene, (i) Abundant. (3) Were here 

 in 1 86 1. Another correspondent says 

 they were abundant in 1861, and that 

 in 1871 " there were quite a number 

 on the rivers, more than usual ; but 

 not in great force." 

 Hamilton, (i) In small numbers. (3) 

 Were here seventeen years ago. 

 SOME doubtful reports. 

 Mr. Meredith, a member of the Senior 

 Class of the Agricultural College, and a 

 resident of Taylor County, informs me that 

 there were no Cicadas in that county this 

 year, but that they toere there in 1863. He 

 says he " is certain as to the last date." 

 Unless there is some mistake in this, we 

 have here a small area of a third brood — 

 Professor Riley's Brood No. XV. [See 

 ist Mo. Ent. Rep. p. 36.] 



A Page County correspondent reports 

 none this year, and says that the only one 

 he has seen for many years was one he 

 caught in 1S64. Professor Todd, of Tabor 

 College, Fremont Co. reports that he trav- 

 eled e,\tensively in Nebraska and south- 

 western Iowa in June of this year, and that 

 he " neither heard nor saw one," He says 

 further, " I find some old settlers who say 

 they have never seen them. Two or three, 

 however, have told me that some year be- 

 tween 1850 and i860 they were abundant 

 in some localities." 



I incline to the belief that we must make 

 here due allowance for the well known de- 

 fective memory of the average man, and 

 include Taylor and Fremont counties in 

 the area of the brood of 1861. This would 

 carry the western boundary line from Cass 

 Co. to the northwest corner of the State, 

 and would add six counties to the area as 

 already made out. I have indicated the 

 direction of this line on the map by 

 a dotted red line. It will be seen to in- 

 clude Adams, Ringgold, Taylor, Page, and 

 all or part of Fremont and Montgomery 

 counties. This addition, if made, carries 

 the whole number of counties in the area 

 of this brood up to thirty-nine or forty. 

 As Professor Riley in the Report 



above referred to says that in 1861 the 

 Cicadas [his Brood XIII] were at St. Joseph 

 in northwestern Missouri, it is probable 

 that this interpretation of the testimony 

 from southwestern Iowa is the correct one. 



It will be noticed that in many cases in 

 the " E.xtracts " given above, the testimony 

 is that there were fewer Cicadas in 1878 

 than when they were present last, /. ^., sev- 

 enteen years ago. This fact, which is in- 

 teresting in itself, may possibly afford an 

 explanation of the fact that no Cicadas 

 were seen this year in the southwestern 

 counties. Possibly the decrease so generally 

 noticed throughout the area of the brood, 

 was simply much greater here than else- 

 where. 



Is this brood dying out ? We can only 

 begin to guess the answer after the next 

 seventeen years shall have passed. 



some notes on the brood of 1 87 1. 



Incidentally I have obtained some valu- 

 able information 'regarding the area occu- 

 pied by the Cicadas of the Brood of 187 1, — 

 Riley's Brood V, — the results of which I 

 give below. 



Twelve counties reported that in 1871 

 the Cicadas were more or less numerous. 

 These are so distributed upon the map as 

 to make it certain that at least four other 

 counties must be added to the area ; so 

 that without doubt we may say that this 

 brood occupied sixteen counties, or an area 

 somewhat less than half as large as that of 

 the brood of 1878. 



The boundary line, as I have approxi- 

 mately drawn it [on Map I] runs from 

 Louisa Co. to Tama Co. at a distance of 

 some miles south of the north line of the 

 brood of 1878 ; from Tama Co. it passes 

 by an approximately straight line to near 

 the northwestern corner of the State. I 

 have definite information as to their occur- 

 rence in the following counties : viz. Louisa, 

 Johnson, Iowa, Poweshiek, Clinton, Cedar, 

 Jones, Benton, Dubuque, Delaware, Bu- 

 chanan and Clayton. Doubtless they also 

 occurred in Muscatine, Scott, Jackson and 

 Lima. 



There is some uncertainty as to the west- 

 ern boundary of the area occupied by this 



