220 HEMIPTEKA. 



same proportion, " a man of ordinary stature should be able 

 at once to vault through the air to the distance of a quarter 

 of a mile." Some of these leaping harvest-flies have the 

 face nearly vertical, and the thorax very large, tapering to 

 a point behind, covering the whole of the upper side of the 

 body, and overtopping even the head, which is not visible 

 from above. These belong chiefly to the genus Membracis, 

 to which allusion has already been made ; and, as they are 

 found mostly on the limbs of trees and shrubs, they may 

 receive the name of tree-hoppers.* In others the face slopes 

 downwards towards the breast, the thorax is of moderate 

 size, and does not extend, much, if at all, beyond the base 

 of the wing-covers, and does not conceal the head when 

 viewed from above. Some of the insects, with this small- 

 sized thorax, are familiarly called, in English works, cuckoo- 

 spit, and frog-hoppers, and to others may be applied the 

 name of leaf-hoppers, because they live mostly on the leaves 

 of plants. 



The thorax differs very much in shape in different kinds 

 of tree-hoppers (Membkacididje), and the variations of this 

 part are productive of many odd forms among these insects, 

 and particularly in foreign species. Among the species in- 

 habiting Massachusetts, there are some in which the thorax 

 forms a thin and high arched crest over the body, as in 

 Membracis camelus of Fabricius, and the vqm of my Cata- 

 logue. 3 To these the name of Membracis, which means 

 sharp-edged, is most applicable. In other species (M. emar- 

 ginata and tinuata of Fabricius, and concava of Say 4 ) the 

 crest of the thorax is deeply notched on the top. In others 

 the whole of the thorax is not elevated longitudinally in the 

 middle, but only in some part; thus M. Ampelopsidis 5 has 

 an oblong square crest on the middle of the thorax ; M. bi- 



* Mr. Rennie, in the " Library of Entertaining Knowledge," has misapplied this 

 name to the Cicadas, which do not leap. 



[ 3 Both belong to the genus Smilia, Amyot. — Uhleb.] 



[* M. emarginata, tinuata, and concava belong to Etililia, Amyot. —Uhlee.] 



[6 M. ampelopsidie belongs to Telamona, Fitch. — Uhlek.] 



