201 



Selecting the more distinctive sand Orthoptera of the Illi- 

 nois valley district, only three of which {Syrbula admirabilis, 

 Spharagemon bolli and Melanoplus atlanis) have been found in 

 Champaign county in dry situations, and comparing them with 

 those of other sand regions, the results are especially significant. 

 The principal sand areas examined by Blatchley were two: the 

 area of northeastern Indiana near the lower end of Lake Mich- 

 igan, and that of the Wisconsin morainic outwash in Vigo 

 county, southern Indiana, near Terre Haute. Opportunity is 

 thus afforded for a triangular comparison, the Illinois locality 

 being about midway between the two in latitude. There are 

 36 species in the comparison, 32 of which are in the Illinois 

 district, 17 in the lake region, and 12 in Vigo county. Only 

 four of the list are common to all three localities, but that is 

 apparently because the Vigo county area is not so sandy as the 

 others, these four being species of dry, but not necessarily 

 sandy, ground. They are 



Spharagemon bolli Melanoplus atlanis 



Sehistocerea alutacea Melanoplus luridus 



Five more Vigo county species occur also on the Illinois 

 valley sand, but are not recorded from the Indiana lake region. 

 These are 



Tettix arenosus Melanoplus impudicus 



Syrbula admirabilis Melanoplus minor 



Ageneotettix scudderi 



The presence of A. scudderi and M. minor in this series is a 

 little strange; the others increase in numbers southward and 

 hence were not found in the more northern situation. 



One species (Nomotettix compressus) common to the two 

 Indiana localities, although it occurs also in Illinois, has not 

 yet been taken in the Illinois valley sand region. 



Of the species common to the Illinois valley and the Indi- 

 ana lake region there are 11 not found in Vigo county, most of 

 them decided sand lovers. The four marked with a star are at 

 or near the eastern limit of their range; the others reach the 

 Atlantic coast states. The list is as follows: 



