228 NATURAL HISTORY OF ARTHROPODS. 



It is found only in the United States, and is best known in the region east of the 

 Mississippi River, although it extends west into eastern Kansas. Areas of variable 

 extent are occupied by it, and in each of which it appears at different years. Thus a 

 very large brood extends interruptedly from northern Vermont to Georgia, and thence 

 to Michigan and Illinois, whicli was first recorded as appearing in 1715. This has 

 been traced at intervals of seventeen years until 1868, and consequently will next 

 appear in 1885. Sixteen distinct broods have thus far been made out, of which 

 four have appeared in New England ; the same number in New York, and in Illinois, 

 extending into Missouri; seven in Pennsylvania; three in North Carolina and Vir- 

 ginia; two in Maryland; one in Kansas and Indian Territory; and one in each of the 

 States, South Carolina, Alabama, Tennessee, Kentucky, Arkansas, and Indian Terri- 

 tory; while only one is in Delaware, and that an extension of the one in southern 

 Maryland. 



Not only do these insects come forth at intervals of seventeen years, but there are 

 three broods which appear at intervals of thirteen years. One of these belongs to 

 Mississippi and Louisiana ; a second to southern Illinois and eastern Missouri, and the 

 third, which is quite extensive, spreads from southern Illinois, through Missouri to 

 Louisiana and Indian Territory, and also into Kentucky, Mississippi, Alabama, and 

 Georgia. In Maryland the brood of 1868 swarmed in countless numbers along the 

 edges of the forests and in places where trees had previously stood. The ground in 

 many places was honeycombed by their numerous holes, and the later specimens were 

 smaller and blacker than the others. A marked difference in their note was observed, 

 which was quite in contrast with that of the year 1851. In the year last mentioned, 

 they swarmed in many of the same localities, as later, but then they seemed to 

 delight in a chorus while sounding the notes resembling fa-rrho. In 1868, however, 

 there was rarely a chorus, comparatively few uttered the familiar sounds, many males 

 were perfectly mute, and single individuals would give forth a short, sharp, inter- 

 rupted shrill noise, or only a few stifled cadences. 



Grandest and most conspicuous of all this group is the rich orange-colored Dun- 

 dtibia imperatoria. It is a native of Borneo and Nepaul, measures eight inches across 

 the outspread wings, and is the largest Hemipteron yet known. Thopha saccata is 

 another very large and rich wine-brown species, in which the drums spi-ead out on 

 each side of the body like great pouches. It is a native of Australia. 



The species figured on our plate (fig. 9) is the superb steel-blue, orange-banded 

 Tacua speciosa, common in Bengal and other parts of India. 



Numerous genera have been separated from the old genus Cicada, some of which 

 are finely colored, curiously marked, as if in imitation of butterflies ; and others are 

 variously modified in the shape of the thorax and head, while still others have the 

 drums reduced to mere short scales, or have them spread out to cover the entire 

 under-side of the abdomen. 



The genera Platypleura, Gceana, Tosena and allies have the wing-covers adorned 

 with opaque bands of brown and other colors, or they are black ; while the abdomen 

 is uniformly blood red, or black with a few yellow spots. These belong to China and 

 the adjacent countries, while the first-named genus is represented by species in nearly 

 all the countries and islands between Japan and the Cape of Good Hope. 



The new world forms generally have the wings transparent, or with only a few 

 fuscous spots on the outer ends of the wing-covers ; but a notable exception occui-s in 

 the Brazilian Carineta formosa, in which the black head, ornamented with a red line, 



