180 XORTir AMERICAN OEDIPODINAE foRTHOPTERA ; ACRIDIDAE) 
ly hu'fi;!'!' licad, lai'ger o;onoi'al size', la-oadcr fastisiuiii, in the pro- 
iiotuin ])('inf>; as an av('raj>:e ])road(a' cephalad and less decidi'dly 
d('l)lana1e caudad on disk, lateral angles hardly marked on ineta- 
zoiud disk; eaudal tiliiae usually pale. 
Simjle — Figured 9 ; Summit of hills at head of Afam- 
modi Hot Springs, Yellowstone National Park, W^yoming; eleva- 
tion, 7000 feet. August 8, 1004. (AT. Heliard.) [Ilebai'd ('ol- 
h'ction, Typ(' no. 72.] 
Fully tyi)ieal material of this suhsiieeies is before us from lo- 
ealiti(\s ('xtimding from (llenora, Bi'itish ('olumbia. (d8° N, 181° 
W), south to northern Foloi'ado (Dutch (leorge and Virginia 
Dale) and northern Utah (Ogden C’anyon, Uity (’reek C’anyon, 
Salt Lake \4dley and Logan); west to eastern Idaho (Salmon 
City and Henry Lake), east to eastern Alontana (Clendive and 
Powd('i'ville). Atypical material showing tendencies toward C. 
rahuhi is present from northeastern Wyoming 
(Ni'wcastk') and northwi'stern Nebi'aska (Bad Lands of Sioux 
Couidy and Cordon); similarly gi’aded material showdng tenden- 
ci(‘s toward C. rahuUt altior is before us from Hecla, Wyoming, 
and Arai)l(‘ Peak, Salt Lak(' County and Cedar Alountains, Iron 
County, Utah. ATatc'rial iidi'rnu'diab' bi'twiam C. ridudu rdhuhi 
and C. fdhuld ndjrdfasciatds i-eju'esiMds localitic'S in southern 
.Manitoba (Awcaiu' and Ti('esbank) and the Black Hills ri'gion 
ol South Dakota. Similarly int('i'm(Mruit(‘ mati'rial between C. 
rdhdid vdhdld and C. rdhuld dllior is from extrenu' soutlu'i'ii Afon- 
tana ( W'est (udiatin Canyon), the Big Horn Alountains, Wyo- 
ming, sont hwest(‘rn Wyoming (Ciauh' (’anyon), northern (Park 
City) and eastca n (Sicai'a La Sal) Utah, and sonthwc'sti'rn (’olo- 
rado (Dolor('s). It is maa'ssaiy to hav(' a clear coma'ption of the 
topogi'apliy of tiu' country involv(‘d,t() ai)pr(‘clat(' t lu' ridat ivity 
ol lli(> loealit i('s illustrating tlu' inbu'gi'adat ion of C. rdl)dld rahtild 
and C. rahdld dltior. 'This is dm' to tlu* fact that the formei' oc- 
curs at lowei’ ('levations and over broach'i' ('xpansi'S of country, 
while dlhitr is l ypic;dly a form of circnmscrilx'd dist ribtd ion in 
eonniry ol eonsidera I )le (‘leva! ion and in art'as appa!'(‘n(ly dis- 
eoniM'd ed. 
.Seiccici I l)y Itcliii ;ni(l I lei), '11(1, l’|•l)e. Acail. Xat. Sei. IMiila., I‘,II2, 
I'. IOC), (l',(|_p. 
