199 



part of the Mississippi valley, none of them are in this immedi- 

 ate vicinity, and it seems remarkable that the distinctive sand 

 fauna should be so well represented in so restricted an area. 



Geographical Distribution of the Species. 



Professor A. P. Morse has truthfully said of the Acridiidce 

 ('99, p. 332): "Locust distribution is primarily and very dis- 

 tinctly climatal in character. * * * In its details it is influ- 

 enced to a very high degree by physiography and its attendant 

 conditions, such as character of the soil, humidity, etc. In its 

 broader features it is eminently characteristic of life zones and 

 regions. * * * It is in many cases dependent on and con- 

 firmatory of geological changes. For these reasons and those 

 noted at the beginning, viz., wide distribution, terrestrial and 

 conspicuous habits, numerical abundance, size, etc., the family 

 and its distribution are of high importance in a study of life 

 zones in their relation to agriculture, and of faunal regions in 

 their relation to general science." 



The Acridiidce of the sand region received my especial at- 

 tention, and, fortunately, the work of Blatchley ('03), Bruner 

 ('97), and Gillette ('04) has furnished very satisfactory lists for 

 a comparison of species with those of neighboring states in the 

 same faunal zone. 



There are now known from the United States and Canada, 

 in round numbers, about 650 Acridiidce. Blatchley has listed 64 

 in Indiana. McNeill's Illinois list ('91) was somewhat incom- 

 plete, and contained only 55 species. Our present Illinois list 

 numbers about 78 species, to which may properly be added for 

 this discussion four species found by Blatchley near the Illinois 

 line, but which we have not yet searched for in the same kind 

 of situations near by on our side of the line. This makes a 

 practical total of 82 species for Illinois. Conversely, we have 

 found in eastern Illinois, although not near the boundary line, 

 two species which probably occur in Indiana, though not listed 

 by Blatchley. Bruner has recorded 150 species in Nebraska, and 

 Gillette 133 for Colorado. Groups of species variously recog- 

 nized by different authors have been equalized in these counts. 



