THE SEVENTEEN-YEAR CICADA. 
97 
spine shorter than in that species, while the snag or supplementary tooth is larger and 
nearer the end; the next spine, the basal one of the series of five, is three times as 
large as the next one, while in C. pruinosa it is of the same size, or, if anything, 
smaller. The toe joint (tarsus) projects over two thirds of the length beyond the end 
of the shank (tibia), while in the other species it only projects half its length. The 
terminal segment of the body is rather larger than in C. pruinosa. The body is shin- 
ing gum-color or honey-yellow, with the hinder edge of the abdominal segments 
thickened, but no darker than the rest of the body. Length, one inch (.90 to 1.00); 
width, about a third of an inch (.35), being rather smaller than that of C. pruinosa 
and much larger than that of C. rimosa. 
Fig. 36.— The seventeen-year Cicada (c) and pupa (a. b): d, position of eggs (e) ; /, larva. (After Riley.) 
For a farther account of this Cicada the reader is referred to Prof. 
Kiley's report of the U. S. Entomologist for 1885, and to Bulletin No. 8, 
of the Division of Entomolosry, which contain fall information regard- 
ing the differeut broods which appear in different years. From his 
observations it appears that the development of the larva is extremely 
slow, and when six years old it hardly attains one-fourth its full size. 
Moulting also takes place more than once a year, so that there are prob- 
ably twenty-five or thirty changes of skin in all. Riley, also, has rarely 
found it more thau two feet below the surface during the first six or 
seven years of its life, and almost invariably iu an oval cell, and more 
often away from roots than near them. Yet it can descend to great 
depths, one writer stating that he had found it 20 feet below the sur- 
face. "As the time approaches for the issuing of the pupa it gradually 
rises nearer and nearer to the surface, and, for a year or two before the 
appearance of any given brood, this pupa may be dug up within one or 
two feet of the surface." 
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