XVIII. 



i 



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i^ 



Fig. 1. Bunch-grass association uS.';>;u spartta. uu tup of a hill, showing the open character of the 



vegetation. The trees In the backin"oumi are not nAtWe.~.\frlanoplus ntifjustipetinvs, 



Ageneotettix scudderi. Mestohregma thomasi. Hippisciis rugosus. anti Slu- 



tillidcp a,re common, and in early summer Hippiitcus pkctni- 



copteriis and //. haldemnnii. Conocephalus 



rohiistus also occtirs here. 



Fig. -j. a single plunt ..t Sju.roh.du 



ri/pt(tndni8 growing on blow-sand has built up a conspicuou.s 

 mound beneath it. 



