DERMAPTERA AND ORTHOPTERA 277 



types that developed in areas of our Southwest, or it may have been 

 intrusive in our area from Mexico, though I am more incHned to 

 place its origin as north of the Mexican line, since one of the three 

 main elements of the genus does not, as far as we know, reach 

 Mexico, and it is, with us, always an Upper Sonoran or Transition 

 species. A second of these main elements is restricted to the western 

 section of the southern half of California and several areas of Baja 

 California, while the third is broadly distributed from east-central 

 Texas west to west-central Arizona and northward over the Camp- 

 estran region to South Dakota. 



ORDER ORTHOPTERA: SUBORDER ENSIFERA 

 Superfaniily Tettigonoidea 



Family Tettigoniidae. Passing now to the great assemblage of 

 what we Americans call the "katydids," but which are elsewhere, in 

 the English-speaking world, referred to as "long-horned grasshop- 

 pers," or technically the Tettigoniidae, we have first the virtually 

 cosmopolitan subfamily of the Phaneropterinae. This is represented 

 in western North America by eight endemic genera, none of which is 

 Holarctic, and by one, Microcentrum, the " angular-winged katydid," 

 that is clearly Neotropical in origin and is much more variedly de- 

 veloped in that region. This genus reaches on one hand to California, 

 and on the other is broadly spread over the interior and eastern 

 United States, but does not reach high altitudes in the Cordilleran 

 section. One genus, Platylyra, is endemic in the California coastal 

 mountains, and probably represents a relatively early development, 

 perhaps from fundamentally Neotropical ancestors. The genus 

 Insara was certainly Neotropical in origin, but it clearly has been in 

 and has undergone a considerable part of its evolution in the broad 

 Sonoran region, developing there at least four lines, one of which 

 lives only on the creosote bush (Covillea). Other species of Insara 

 range from Mexico to Panama, while related genera are known 

 from Panama and northern Argentina. The genus Brachyinsara, 

 which as clearly has had a common ancestry with Insara, is known 

 only from extreme southern California and Baja California. 



The genus Arethaea, composed of spectral, ghostlike species, is 

 clearly a development of the Sonoran center. Certain of its species 

 are found in northern Mexico, but the majority occur within the 

 limits of the United States, ranging northward in the Great Plains 



