DERMAPTERA AXD ORTHOPTERA 259 



broad sweep in the southwestern United States and Mexico by an 

 extension of its range covering much of the state of CaHfornia. 



The tetrigid subfamily Batrachideinae is one that has, funda- 

 mentally, a "Gondwanaland" type of distribution and perhaps of 

 origin. The genera are limited to the Americas, particularly the 

 Neotropical section, and to the Ethiopian, Oriental, Alelanesian, 

 and Australian regions. Their greatest development is in South and 

 Central America, where eleven of its sixteen genera occur. One 

 genus is Melanesian and Australian, one is Oriental, and two are 

 Ethiopian, while a single one, Paxilla, is a Nearctic endemic, found 

 only in the southeastern United States. The genus Tettigidea is 

 clearly of Neotropical origin, as it has many species limited to South 

 and Central America, but it became established in our continent, 

 and particularly in eastern North America, relatively early in the 

 invasion of our continent by Neotropical types. There are four well- 

 marked lines of the genus in the eastern United States, with clearly 

 marked, related species in Mexico and Central America, the range of 

 none of which, however, is contiguous to those of its relatives in the 

 southeastern and central United States. One of these lines, T. 

 lateralis, is much more broadly distributed than the others over the 

 eastern and central portion of North America, occurring westward to 

 parts of the Cordilleran region and to certain areas on the Mexican 

 boundary. 



Family Eumastacidae. This is, for the Orthoptera, an old assem- 

 blage, on the basis of present knowledge probably older than the 

 true grasshoppers or Acrididae. The oldest fossil definitely referred 

 to the Eumastacidae is Promaslax of Handlirsch, from the Oligocene 

 of British Columbia. From the Miocene of Florissant, Colorado, 

 three species of the genus Taphacris have been described, and these 

 have been considered eumastacoid by Cockerell, Tillyard, and 

 Zeuner. A species described from the Oligocene of Baden, Germany, 

 by Theobald, has also been referred to this family by Zeuner, who is 

 probably the most capable student of fossil Saltatoria in recent years. 

 Therefore, the Eumastacidae seem to have appeared in both hemi- 

 spheres, relatively early in the Caenozoic, at a time of probably 

 greater warmth than today. 



The greatest development of the Eumastacidae at present is in 

 the tropics of both hemispheres, with the maximum generic differ- 

 entiation in the Indo-Malayan and Oriental Regions, followed by the 



