74 GENERAL ZOOLOGY 



the antennae longer than the body. Many show protective 

 resemblance in color or form to the leaves among which they 

 live. 



Family 4. Gryllidce; crickets. The mole-crickets have 

 enormous front legs and spend their entire lives burrowing 

 underground; the true crickets are the common varieties 

 whose shrill chirps are heard in the fields or about houses; 

 the tree crickets live above ground in vegetation and have 

 very harsh, guttural voices. 



Family 5. Mantidce; praying mantids, devil-horses. In 

 these insects the first pair of legs form prehensile organs 

 which are used in capturing insects, spiders, etc. Mantids 

 live in bushes or trees and are most abundant in the 

 warmer parts of the earth. 



Family 6. Phasmidce; walking-sticks. These curious 

 orthopterans have small legs suited for walking. Their 

 form resembles the twigs on which they live. They are 

 very slow and depend upon their protective resemblance 

 to escape their enemies. If disturbed they often remain 

 motionless for hours at a time, lest they betray themselves. 

 Their food consists entirely of leaves. 



The following key* will separate representatives of the 

 Orthoptera into their proper families: 



1 (6) Legs equal or nearly equal in size; no sound-producing organs 



(Suborder, Non-saltatoria), 2 



2 (3) Body short, broad, oval, depressed; head almost wholly con- 



cealed beneath the thorax; legs compressed, Family, Blattidce. 



3 (2) Body elongate, narrow; head free, not covered by thorax; 



legs slender and not all compressed 4 



4 (5) Front pair of legs fitted for grasping Family, Mantidcs. 



5 (4) Front pair of legs much like the others. . . .Family, Phasmidce. 



6 (1) Hind legs fitted for leaping, or front legs greatly enlarged for 



burrowing; organs for producing sound usually present 



(Suborder, Saltatoria), 7 



* In using the key the statement after a particular number is always 

 to be compared with that appearing after the number in parenthesis, which 

 occurs elsewhere in the key. For example: 1 is compared with 6, 2 with 3; 

 3 with 2, etc. 



