OKTHOPTEKA OF INDIANA. 133 



(dv.) or "scutellum," (sv.) is often depressed, or separated from 

 the remainder. Its bounding walls are termed "lateral carinoi'" and 

 often a "median carina'' divides it into two parts. The front por- 

 tion, or apex, often called the "fastigiuni," is variable in form, and 

 its characters are also much used. On the outer side of, and a little 

 below the front half of each lateral carina of the vertex, there is, 

 in many Orthoptera, a little space or concavity bounded by elevated 

 ridges. These spaces are the "lateral foveolw-,'' (f.) and their varia- 

 tions in size and form also afford characters much used in classifi- 

 cation. 



The Thokax and Its Appendages. 



The middle region of the body is called the "tliorax.'' To study 

 its parts aright, the wings and legs attached to it should be removed; 

 when it will be seen to colisist of three rings or segments. These 

 are known as the "protliorax," "mesothorax" and "metathorax." With- 

 in these rings are located the muscles for moving the wings and legs; 

 as well as some of the digestive organs. 



Fig. 1). Lateral view of the prothorax of a locust. 

 (After Lugger.) 



The Prothorax of the locust (Fig. 6) has its sides and dorsal 

 surface covered by a large, sun-bonnet shaped piece known as the 

 "pronotum" (pro.). This varies much in shape and size in the dif- 

 ferent families of Orthoptera. Its upper surface is called the "disk," 

 and its sides, the "lateral lobes." Raised lines known as "lateral 

 carincB" usually separate the disk from the sides, while a third line, 

 the "median carina,'' runs- lengthwise through the middle of the 

 disk. This may be "high" or "low," "crested," "arched," "distinct," 

 "aborted," etc. It is usually cut by one or more notches formed by 

 shalloAV grooves or ^'sulci" which cross the disk of the pronotum and 

 extend down its sides. Tlie hindmost of these sulci, or grooves, 

 divides the disk of the pronotum into two parts known as the "pro- 

 zona" (pz.) and "metazona" (mz.). The fore and hind margins of the 

 disk of pronotum may be "truncate," "rounded," "angled," 



