482 PROCEEDINGS OF THE ACADEMY OF [June, 



They are usually rich in moisture and available plant-food ele- 

 ments. 



9. The soils of the Coastal Plain are prevailingly relatively coarse 

 sands of detrital origin. They are frequently deficient in moisture 

 and available plant-food elements. 



10. From an Orthopteran faunistic standpoint, four primary 

 subdivisions are recognizable in the eastern Pennsylvania-New Jersey 

 region, namely, Appalachian, Piedmont, Coastal and Pine Barren. The 

 first two are subdivisions of the Transition Zone, the last two of the 

 Coastal Plain. Each may be regarded as a local centre of dispersal. 



11. From the same standpoint, the Highlands, the Middle District 

 and the Cape May Peninsula are to be considered as of secondary 

 value, each representing a sort of tension zone in which there is an 

 intermingling, overlapping or interdigitation of species from adjoining 

 primary districts. 



12. The Orthopteran fauna of the Appalachian District has never 

 been adequately studied from a faunistic standpoint. The available 

 data indicate that it is fundamentally Piedmont in type with the 

 addition of a number of distinctively northern (boreal) species. 



13. The Orthopteran fauna of the Highlands has also never been 

 adequately studied. The available evidence indicates that it is 

 thoroughly Piedmont in type with a few stragglers from the Appala- 

 chian District. 



14. The Orthopteran fauna of the Piedmont Plateau is predomi- 

 nantly mesophilous. This is correlated with the presence of a 

 dominant mesophytic type of vegetation. 



15. The Orthopteran ecological associations of the Piedmont 

 Plateau are usually not clearly delimited. In a general way three 

 such groups correlated with the relative moisture content of the 

 habitat may be recognized. These are the mesophilous, xerophilous 

 and hygrophilous associations. Each of these may exhibit an open- 

 country or campestral phase and a woodland or sylvan phase. 



16. The mesophilous association is characteristic of rich loamy 

 soils and a luxuriant vegetation, of which the dominant members are 

 bright green, succulent, sod-forming grasses. 



17. The xerophilous association of the Piedmont Plateau consists 

 exclusively of the humicolous subdivision; arenicolous and saxi- 

 colous species are lacking owing to the absence of pure sand and the 

 scarcity of bare rock surfaces. This association typically occurs on 

 uplands or hillsides where the soil is unsuited for agricultural purposes. 

 The associated vegetation is of a mildly xerophytic tj^'pe. 



