1914.] NATURAL SCIENCES OF PHILADELPHIA. 473 



The Coastal Plain affinities of these lowlands is shown in the 

 presence of such Orthoptera as Paroxya Jloridiana, Conocephalus 

 robustus, C. nebrasceiisis and C. palustris, and in the comparative 

 abundance of such forms as Orphulella pelidna and Scudderia texensis. 

 On the other hand, the influence of the Piedmont is evidenced by the 

 abundance of species like Dichromorpha viridis, Orphulella speciosa, 

 Stenohothrus curtipennis and Encoptolophus sordidus. 



In this narrow strip of Coastal Plain country the most abundant 

 grasshopper is Melanopliis femur-ruhrum. It far outnumbers all 

 the other species and is especially abundant in the low humid tracts 

 adjoining the river marshes. Less common, but quite frequent 

 species are Dichromorpha viridis, Stenohothrus curtipennis, Dissosteira 

 Carolina, Chortophaga viridifasciata, Encoptolophus sordidus, Orphu- 

 lella speciosa, Orchelimum vulgare, Melanoplus differentialis, M. 

 femoratus, Xiphidium fasciatum, Orchelimum spinulosum, Xiphidium 

 strictum, X. hrevipenne and Arphia xanthoptera. Other forms of 

 not uncommon occurrence are Orphulella pelidna, which in spots 

 may be a close rival of its congener, 0. speciosa, Conocephalus robustus, 

 C. triops, and Scudderia texensis. The remaining species are more 

 or less infrequent or local in distribution. 



Further south at Newcastle, Delaware, the Coastal Plain com- 

 ponent of the fauna becomes more prominent, due to the influx of 

 the more strictly Coastal types, such as Tryxalis brevicornis, Syrbula 

 admirahilis and Orchelimum herbaceum. My study at this locality 

 was very superficial, but during a few hours' collecting there I noted 

 the following species: 



Tryxalis brevicornis "* Melanoplus differentialis 



Syrbula admirahilis " femoratus 



Dichromorpha viridis Paroxya floridiana 



Orphulella speciosa Scudderia texensis 



" pelidna Conocephalus triops 



Arphia xanthoptera Orchelimum herbaceum 



Dissosteira Carolina Xiphidium fasciatum 

 Melanoplus femur-rubrum 



East of the Delaware River in New Jersey the Middle District 

 forms a zone varying between 10 and 25 miles in width. The under- 

 lying geological formations are unconsolidated sediments of sand, 

 clay and glauconitic marls with occasional shell beds belonging to 

 the Cretaceous and Miocene Ages, but, except where they have been 

 exposed by stream erosion, these are everywhere covered by a sheet 

 of Pleistocene sand and gravel. Close to the Delaware- Atlantic 



