﻿March 1895 ] LaNDER. DoMES OF CiCADA SEPTENDECIM. 33 



DOMED BURROWS OF CICADA SEPTENDECIM. 



By Benjamin Lander. 



In 1877 a remarkable phenomenon connected with the advent 

 of the periodical Cicada — the so-called seventeen-year "locust", 

 (Fig. i) was observed at Rahway, N. J. — On opening a cellar 

 which had been closed up to the time that the pup?e (Fig. 2) issued 

 from the ground, the floor was found to be studded with small, 

 hollow, cone-like structures, built of mud, which had been con- 

 structed as extensions of Cicada burrows. The attention of 

 Professor J. S. Newberry having been called to the circumstance 

 he deemed it of such importance that he secured specimens, and 

 obtained a detailed statement of the features of the case, signed 

 by several leading citizens of Rahway, and published the account 

 in the School of Mines Quarterly of Columbia College, Jan. 1886 ; 

 and in a separate illustrated pamphlet. As the Professor made no 

 mention of ever having seen like structures before, the inference 

 is natural that he had not.* Indeed, so rare were they prior to the 

 advent of the same brood in 1894, that few entomologists had seen 

 them, and no accurate description existed. Last year, countless 

 numbers of these hut-like domes were observed at various places. 



On the fourth of May 1894, while in the woods on the summit 

 of South Mountain, at Nyack, N. Y., I came upon a spot that had 

 recently been burnt .over. On this area I observed vast quantities 

 of the Cicada structures, entirely closed, averaging about two and 

 a half inches in height; the aggregation ending at the very edge 

 of the burnt section. So thickly studded was the ground that 

 often eight or ten would be found in the space of a square foot ; 

 in one case I counted twenty-three in such a space. Subsequent 

 explorations showed that the Cicada city extended over an area 

 of not less than sixty acres. Eight large aggregations were dis- 

 covered by me on top of the Nyack hills and the Palisades, covering 

 many acres, and one near a stone quarry at a lower elevation ; 

 none of them in a place subject to overflow. Later, when only 

 the ruins of the domes remained, I visited two areas where large 

 numbers had been found ; one in ground thinly covering massive 

 sandstone, and another hard by a quarry, where the top soil was 

 thin. An account of the discovery was published in The New 

 York Times, and in the Scientific American of Oct. i6th. I offered 



* Previouslv described and figured bv Walsh and Riley (see Am. Ent., 

 Vol. I, 186S, p. 65). ' Wni. B. 



