182 NORTH AMERICAN OEDIPODINAE (oRTHOPTERA; ACRIDIDAE) 
The differential features of the present sii])species, ainonp; 
the forms of rahula, are generally narrower tegniinal apices, aver- 
age more elongate wings with slightly more acute apices, weaker 
incrassation of the heavier radiate veins of the wings and the 
shar])ly indicated and generally complete and solid dark wing 
bar. These features other than the wing bar all show some vari- 
ation in the series before us, and the race is not structurally as 
definite as mhula altior. The wing bar, however, is sharp and 
contrasted in ty})ical material, and less marked and broken in 
atypical individuals. 
This geographical race is a large, generally pale colored, one, 
tyi)ical over a considerable portion of the Great Plains region, 
particulai'ly in the sandhill country, its area of distribution ex- 
tending fi-oni south-central South Dakota (Capa) south to south- 
centi’al Kansas (Barber County), west to extreme southeastern 
Wyoming (Pine Bluff's) and east-central Colorado (Pueblo and 
Ci'ay Creek). Typically the subspecies is found north only to 
south('ast('rn Wyoming (Pine Bluffs) and northwestern (Fort 
Bobinson) and central (Dismal River and Broken Bow) Nebraska. 
Mat ('rial from Cdipa, South Dakota is somewhat atypical, while 
a s('ri('s of thirty-three of both sexes from Clen, Nebraska com- 
pris('s mostly atypical individuals, although about twenty per 
(‘('id are typical of nuirafasciatiis. In all from Clen the wing bar 
is lu'arly tyjiical of nuirafascuttn.s, the fluctuations being in other 
ff'atui'es. To understand the intergradation of C. rnhuin rabula 
and C. rahula n'UjrafaHciaius in northwestern Nc'braska it is nece.s- 
sai-y to visualize tlu' iiliysiograjiliy of the country. The (treat 
Plains plat('au th('r(' br('aks off sharply on the north to the Ikid 
I. amis of th(' (di('y('nn(' and 'White Rivers. In the latter tyjie 
of count I'y w(' find material of this species wdiich is atypical of 
rahula rahula] on tlu' sui’face ot the Plains vra find our represent- 
ativ('s iK'ai'ly oi' (|uit(' rahula m'(irafasciatus, which ranges off fo 
lh(' .'^outh ()V('i' th(' Plains and sandhills sections, where in pre- 
f('i'r(‘d ('nvironiiK'ids it occurs as low as 2-480 feef (Broken Bow), 
appi()ximat('ly oiu' thousand f('('t l()W('r fhan the country in 
uhich aty|)ieal rahula rahula occurs in the Ch('y('nne and W hite 
ICivei' B;id bands. ( )n t lu' sloja's of t lu' Sioux Couuty, Nebraska 
cseaipiiK'id , as at (Ih'u, th(' ma4('rial shows ((('finite intei'grada- 
li(»n of the two rac('s. At ('ajia, Soidh Dakota atyiiical nigra- 
fascKilus occurs as low as two thousand feef. d\) the wi'stward 
uigrfifa.sriatus is fidly typical at U'ast as far as Piu'blo, (\)l()ra(l(). 
