226 THE CANADIAN ENTOMOLOGIST. 



One of the most striking peculiarities of brood, XV. in Ohio was its 

 exceedingly uneven distribution within the boundaries of its range. On 

 driving over the country during the midst of the season of greatest 

 activity, one would suddenly find himself in the midst of a din that was 

 almost deafening, and the woods would be browned with discoloured 

 twigs, while within a mile he would find himself in the midst of a silence 

 that from contrast was almost oppressive, while there was not a discoloured 

 twig to be observed. This lack of uniformity in distribution rendered the 

 work of locating the exact boundaries of the brood quite difficult in some 

 cases, as one must often go miles beyond it in order to be quite sure that 

 he had found the last outlying colony. But in other cases the effect was 

 the reverse. In going southward from Painesville, over the P. & W. Ry., 

 which cuts through what is locally known as " Johnnycake Ridge," not 

 a note was to be heard, and not a discoloured twig was to be seen on tree 

 or shrub, but on leaving the cut, which is by no means a long one, the 

 combined notes of the thousands of Cicadas were clearly heard above the 

 noise of the train, while scarcely a tree or bush escaped the attack of the 

 females, and some of them would not have been more thoroughly browned 

 if a fire had broken out among them. In the city of Lancaster they were 

 reported as abundant in the east part of the town, while there were scarcely 

 any in the western portion, and it turns out that the dividing line between 

 this brood and brood XXII. is practically indicated, as nearly the same 

 conditions were observed to occur seventeen years ago. 



The brood is certainly becoming weakened each time it reappears, 

 and the boundaries of its occurrence did not in many cases extend as far 

 as they did when it last appeared, sometimes the difference amounting to 

 several miles. Near Painesville it occurred some three miles nearer to 

 the lake shore in 1846 and in 1863 than it did in 1880 or the present year. 

 It was at Bellevue in 1880, but did not extend so far west this year, and 

 the same is true of its occurrence northward toward the lake. Where it 

 was quite abundant in 1880 it did not appear at all this year. It was 

 reported by two observing correspondents as having been present in 

 limited numbers in Ashtabula county in 1863 and again in 1880, but no 

 trace of it could be found this year. In short, it seems to be slowly but 

 surely dying out, and will in time be known only in history. Brood XXII. 

 is a much stronger one — at least it was in Indiana — but I question if in time 

 the Periodical Cicada is not wholly exterminated in Ohio, and there seems 

 no reason why this should not be true of many other States. The gradual 



