CHRONOLOGICAL ACCOUNT OF DIFFERENT BROODS. 27 
the Prairie Farmer, briefly recording the appearance of Cicadas in Mc- 
Lean Comity. 
Upon reviewing the localities of this brood as now ascertained we find 
that they represent a comparatively narrow curve with the ends point- 
ing northward. The northeastern extremity commences in southeast- 
ern Massachusetts; thence the line goes south to Long Island : thence 
west through Pennsylvania, southern Ohio, and northern Kentucky to 
southern Indiana; thence again bending northward and reaching cen- 
tral Illinois with its northwestern extremity. This large belt is, how- 
ever, by no means entirely occupied by the brood, and two large, com- 
pact central areas are plainly distinguished, one being in southeastern 
Pennsylvania, the other in northern Kentucky and southwestern Ohio. 
To the west there are two detached areas, one in southwestern Indiana, 
the other in central Illinois, while to the east there are again two de- 
tached areas, one on Long Island and the other in southeastern Massa- 
chusetts. 
Brood IX.— Septcndtcim (?)— 1874, 18U1. 
In the year 1H74. and at intervals of seventeen years thereafter, they will probably 
occur in southeastern Nebraska. 
The occurrence of this brood was coinmunieated to me by Mr. Clarke Irvine, of 
Oregon, Holt County, Mo. The brood is most likely confined to the eastern or tim- 
bered portion of the State, and 1 judge it to be septendecim, from the laet that the lati- 
tude is rather more northerly than trededm is known to occur. 
1874. — Whether this brood is a 17-year or 13 year one still remains 
somewhat doubtful, with the probability in favor of the former; but its 
existence and, at the same time, its extent westward to Colorado seem 
to be confirmed by a letter from Mr. J. H. Rice, of Gold Hill, Boulder 
County, Colorado, dated July 31, 1874, stating that the Cicadas oc- 
curred there in 1874, but not very abundantly. While it is true that 
this locality in Colorado is widely detached from that in southeastern 
Nebraska, yet we do not doubt that the Cicadas of both localities be- 
long to the same brood. In these less timbered western States the 
broods must naturally be very much broken up, and appear in scattered 
localities and not in compact regions, as in the timbered States. 
In this connection I would mention that on May 17, 1871', Mr. J. I>. 
.Miller informed me of a brood between the headwaters of the Smoke 
Hill River and Denver City. Colorado, in L858. "Their work was 
plainly visible on a grove of young pitch pines." 11* these Cicadas 
were not stragglers of this Brood IX, but belong to some other brood, 
they would be difficult to place among the broods here enumerated. If 
they are a 13-year brood they could only belong to our Brood VI. which 
is extremely improbable. Moreover, it is not likely that central Colo- 
rado possesses a 13-year brood. If they belong to the 17-year race 
they would indicate a brood not yet enumerated and to be placed 
between my Broods IX and X. Although 1 have no reason to doubt 
the correctness of Mr. Miller's statement, vet it must be remembered 
