50 INSECTS. 



(a) The lacinia (or blade), the innermost part, the part 

 used in biting. 



(5) The galea, spoon-shaped, and covering the lacinia 

 externally. 



(c) The maxillary palpus, a jointed, tactile organ out- 

 side. Count its joints. 



4. A two-lobed labium (or lower lip), bearing below a 

 pair of jointed labial palpi. 



5. A fleshy tongue, between and below the maxillae. 

 Separate these mouth parts, and examine each with a 



lens. Draw. 



II. Thoracic Segments. Note the relative size of the 

 three thoracic segments. Note their peculiarities of form, 

 color, and surface markings. Locate their spiracles. 



III. Wings. Study the wings. Seize the fore wing 

 by its costal margin, draw it forward, and fasten it at 

 right angles to the body. Then in the same manner 

 draw the hind wing forward. Note how it is folded. 

 Compare the two wings in form, color, size, texture, posi- 

 tion, and use. The dry, horny fore wings of grass- 

 hoppers are called tegmina. Find in one of the tegmina 

 five principal veins, costal, subcostal, median, sub- 

 median, and internal, starting outward from its base. 

 Observe that each of the tegmina is marked off into three 

 areas, the costal, median, and internal areas. The 

 median area lies between the subcostal and submedian 

 veins; the costal area, anterior to the median; the internal 

 area, posterior to it. 



Make an enlarged and accurate drawing of a tegmen, 

 naming all the veins and areas upon the drawing. 



It is by rubbing together the lower surfaces of the teg- 

 mina, and the upper surface of the costal vein of the 

 hind wing, that the males of this species produce the 

 sounds called stridulation, in flight. Examine these sur- 

 faces with a lens. 



