1919.] NATURAL SCIENCES OF PHILADELPHIA. 77 



of contrast of the paler lining of the immediate anal angle, is much 

 as in the other species of the genus. The depth of the coloration 

 of the caudal tibiae is gauged by the general tone and pattern. 

 It may be as dull as cameo brown (very dark and recessively 

 colored female from the Illinois sand region), as light as coral 

 red or as rich as scarlet. The latter condition is indicated only 

 in Baboquivari Mountains, Arizona, specimens. 



The small Baboquivari Mountains series is much more brilliant 

 in coloration and averages more lineate (i. e., high percentage with 

 medio-longitudinal bar) than any others. What Mearns has said 

 of the mammals of an adjacent portion of the United States and 

 northern Mexico can be noted in relation to the intensity of colora- 

 tion in these individuals. ''Increased intensity of coloration 

 characterizes the mammals from the valleys containing the ter- 

 minal streams of the great Yaqui River of Mexico, some of which 

 rise on the United States side of the Boundary. "^^ We hope to 

 have more to say in the near future regarding the intensification 

 of color tones and increase in contrast of patterns in Orthoptera 

 from certain sections of the Mexican Boundary region. 



Distribution.- — The range of this species extends from the Yellow- 

 stone and Missouri Rivers region of eastern Montana and western 

 North Dakota, south to central (Kerrville) and western (Chisos 

 Mountains) Texas and northern Durango (Villa Lerdo), Mexico; 

 east to north-central Illinois (vicinity of Havana and Bishop), 

 southwestern Iowa (Hamburg), eastern Oklahoma (Cherokee Na- 

 tion) and central northern Texas (Dallas region) ; west to southern 

 Montana (Little Big Horn River), west-central Colorado (Clear 

 Creek Canyon) and southern Arizona (Baboquivari Mountains). 

 The latter region is separated from the other localities from which 

 the species is known by an interval of about five hundred miles. 

 This striking isolation of the Baboquivari material would be extra- 

 ordinary, if it were not shared by a number of other steppe species 

 having a similar range. The explanation of this type of distribu- 

 tion is yet to be found. The occurrence of areas of tall grass is, 

 however, a controlling factor within the range of the species. 



The vertical range of this species extends from at least as low 

 as 430 feet (Dallas, Texas) to as high as 9000 feet (mouth of Clear 

 Creek Canyon, Colorado). In Texas alone, the vertical range is 

 definitely known to be from the minimum given above to at least 



=^ Bull. 56, U. S. N. M., p. 74, (1907). 



