238 NORTH AMERICAN EUMASTACINAE (oRTHOPTERA) 



The vertical range of the race is from as low as 4400 feet (Cal- 

 iente) to at least as high as 6000 feet (Crestline). The upper 

 limit of its distribution in the Prescott region is probably higher 

 than the maximum here given, as Mount Union Peak extends 

 from 6000 feet to practically 8000 feet, but we have no altitudinal 

 information concerning the material from that locality. 



Biological Notes. — This race is as thamnophilous as the others 

 of this species. At Caliente it occurred on several bushes, one of 

 which was Kunzia tridentata, on mountain slopes rising from a 

 wash of Meadow Valley (see plate XVI, fig. 1), while at Crestline 

 it was quite numerous on the same bush growing in open stands 

 of Utah Juniper {Juniperus utahensis) and occasional pinyon 

 {Pinus monophylla) on the rolling plateau summit of the Juniper 

 Mountains (see plate XVI, fig. 2). Data with certain of the 

 Prescott material show the insect especially preferred thorny 

 bushes in that region. 



Apparently this form is represented by immature individuals 

 as late as August 24, but is also adult as early as July 9. 



Morphological Notes. — The variation in the angle of the fas- 

 tigium, when seen in profile, is as extensive as in M. c. calif ornica, 

 and in the large Prescott series of both sexes this is quite evident. 

 Viewed from the dorsum, however, the characteristically broader 

 and shorter pronotum is less variable. 



The material from a relatively high elevation in southern 

 Nevada (Crestline) averages smaller than the central Arizonan 

 series, while that from a lower elevation in the same general 

 region of Nevada in size is more like that from the Arizonan local- 

 ities. 



Remarks. — This interesting race is, as far as known, completely 

 isolated in distribution from the other forms of the genus, as we 

 have no knowledge of the occurrence of Morsea in any of its 

 races in the extreme desert conditions of western Arizona, south- 

 eastern California and the lower or more arid portions of south- 

 ern Nevada. Its distribution appears to be restricted to portions 

 of the great Arizona plateau region and its northward continua- 

 tion in southeastern Nevada and probably southern Utah. 

 Its relationship to M. c. californica is close and the separation of 

 the two stocks appears to be a relatively recent development. 



