17 



as very common in blowsand and on dune summits. Resembles fe- 

 male mutillids. 



Phidippiis auda.v Hentz; Peckham, det. April 4, 



A black species with orange spots ; cjuite common hibernating un- 

 der cactus lobes on a dune summit. 



Phidippiis ardcns Peckham ; Peckham, det. June 28. 



A male jumping spider, taken running about on the bare sand in 

 the bunch-grass association. 



Phidippiis mc-cookii Peckham; Peckham, det. October 8. 



A jumping spider with red abdomen, taken in a blowout, close to 

 the Cassia growth. The specimen is a male. 



Order acarina 



Microtroiitbidiiiiii locustanim Riley. July 19. 



This small red mite is a very common parasite of insects, particu- 

 larly grasshoppers. Several specimens were taken on grasshoppers 

 from blowsand at the Devil's Hole. Observed also on Asilidae, Tachi- 

 iiidac, and other insects of the sand prairie. 



Order coi.lembola 



Bntoinobvya sp. ; J. W. Folsom, det. April i. 



Found under logs in sand with considerable humus content. An- 

 other collembolan was found in pure or almost pure sand, but no 

 specimens were captured. 



Order platyptera 



Tevuics fla-inpcs Kollar. July 25, April i, 4. 



The termites are very abundant in sand regions, where they are 

 found under boards. They eat wood tissue, and logs in the woods 

 are often found with most of the interior eaten out. Several colonies 

 containing workers, soldiers, and winged forms were found in April. 

 They are common in the Lake Michigan sand region and on the dry 

 soils of southern Illinois. Widely distributed. 



Order ephemerida 



Hexagcnia hiJincata Say. July 6. 



A dark-colored I\Iay-fly of large size; wings clouded and dark in 

 color. This is the most abundant May-fly in the river. The residents 



