FURTHER RESEARCHES ON NORTH AMERICAN ACRIDIIDJE. ig 



The explanation of this assemblage probably involves several 

 factors: primarily, variety of habitat represented rock, bare soil of 

 sandy road, grass, shrubby undergrowth ; secondarily, aggregation of 

 individuals at a topographical " jumping-ofF place," a phenomenon 

 akin to the assembling of many other insects at the extreme apex of a 

 high hill or mountain summit, which has been repeatedly observed. 



Besides the two prairie species previously mentioned as captured 

 at Ashdown, several others occur in at least the western part of the 

 State. Among these are Orphulella decora, Campy lacantha olivacea 

 and its color-variety acutipennis, and Melanoplus foedus. Orphulella 

 decora lives in grassy fields, by preference of moister character than 

 those inhabited by picturata; Campy lacantha olivacea, a short-winged 

 species, is locally common in herbaceous thickets of various kinds, 

 but commonly of some species of ragweed (Ambrosia bidentata et al.). 



The following list of species captured in western Arkansas is here 

 brought together for convenience of reference ; several others occur 

 and would be secured by a longer search and at other seasons of the 



year : 



Nomotettix cristatus. Trachyrhachis thomasi. 



Neotettix femoratus. Trimerotropis citrina. 



Tettix arenosus. Trimerotropis saxatilis. 



Tettix hancocki. Schistocerca alutacea. 



Paratettix cucullatus. Schistocerca americana. 



Tettigidea armata. Schistocerca obscura. 



Tettigidea lateralis. Schistocerca rubiginosa. 



Tettigidea lateralis polymorpha. Campylacantha olivacea. 



Syrbula admirabilis. Hesperotettix pratensis. 



Amblytropidia occidentalis. Paratylotropidia brunneri. 



Orphulella decora. Melanoplus atlanis. 



Orphulella pelidna. Melanoplus bispinosus. 



Orphulella picturata. Melanoplus differentialis. 



Dichromorpha viridis. Melanoplus femur-rubrum. 



Chloealtis conspersa. Melanoplus foedus. 



Boopedon auriventris. Melanoplus gracilis. 



Arphia sulphurea. Melanoplus impudicus. 



Arphia xanthoptera. Melanoplus keeleri. 



Chortophaga viridifasciata. Melanoplus latens. 



Hippiscus phoenicopterus. Melanoplus obovatipennis. 



Hippiscus rugosus. Melanoplus robustus. 



Dissosteira Carolina. Melanoplus scudderi. 



Spharagemon bolli. Paroxya sp. 



Collecting in Indian Territory was begun on August 4 at Howe, 

 in the eastern part, and continued until August 9 ; on the return from 

 Oklahoma, a half day was spent at Wilburton on the 2yth in examina- 

 tion of a small prairie meadow at that place. 



