26 GUIDE TO INSECTS. 



Table- leg of a common grasshopper, Stenobothrus Ucolor for example, be 



case ' examined with a magnifying glass there will be seen on the inner 



side of the femur a row of tubercles (or modified hairs). These 



rub against a prominent vein on the wing and produce a shrill 



sound. 



So far as is known the large locusts do not produce this 

 sound. 



The eggs are long and narrow, elliptical. They are laid in 

 batches in the ground (1280, 1293). 



Some species are remarkable for the great development of the 

 prothorax, which in some cases covers the whole body. It is some- 

 times arched and crest-like as in Choripliyllum and Hymenotes (1271). 



Fig. 23. 



Hind leg of a grasshopper (Stenobothris bicolor). 

 a, row of tubercles. 



Tettix (1272) and its allies have it prolonged backwards, the tip of 

 the prolongation in some species projecting beyond the end of 

 the body. 



In many genera the forehead is more or less produced and 

 sometimes pointed. This is very noticeable in Tryxalis (1275), a 

 genus which has curiously flattened antennae. Proscopia (1274), 

 a remarkable wingless insect, not only has the forehead produced, 

 but the whole of the upper part of the head is raised, the eyes 

 being elevated with it. 



To this family belong the true locusts, some of which, Tropidacris 

 (1 290) for example, measure nine inches in the expanse of the wings. 

 The chief migrating species are Pachytylus cinerascens (1283), P. 

 migratorius (1282), P. migral oroides (1284), P. marmoratus, Acridium 

 peregrinwn (1 291 ), and in North America Caloptenns spretus. 



