REHN AND HEBARD 369 



are from regions where the species is very rare, if ever native. 

 Frequently individuals are attracted to lights in cities at night; 

 we have observed this in N. exiliscanorus, robustus crepitans (in 

 numbers), retusiis and triops. In the pine barrens of New Jersey, 

 miles from their normal environment, several males of N. lyristes 

 and one of N. palustris were found stridulating vigorously on the 

 low oaks at night. 



Key to the Species Tj-eated 



A. Vertex decidedly longer than wide, not broadly and evenly rotundatc. 

 B. Vertex strongly produced, much longer than basal width; narrowing 

 decidedly to apex which is very narrowly rounded (except in mel- 

 anorhinus) . 

 C. Form robust. (Vertex slender, with ventral surface black as far 

 as or including basal tooth.) 

 D. Vertex exceedingly long, with basal tooth very prominent. Ovi- 

 positor very much longer than caudal femur. Size medium to 

 very large, form not as compact as in nebrasccnsis. 



exiliscanorus (Davis) 

 DD. Vertex not as long, with basal tooth not as prominent. Ovi- 

 positor much longer than caudal femur. Size medium, form 



very compact nebrasccnsis (Bruner) 



CC. Form slender. 



D. Vertex heavy, with ventral surface black as far as or including 



basal tooth. 



E. Vertex moderately prodi5ced, about twice as long as basal width, 



narrowing decidedly to abruptly truncate apex, which is 



broad and weakly rounded. Ovipositor distinctly shorter 



than caudal femur. Size small to large, form moderately 



slender melanorhinus (Rehn and Hebard) 



EE. Vertex very long, longer than in any other species except 

 exiliscanorus. Ovipositor distinctly longer than caudal 

 femur. Size medium, form very slender. 



lyristes (Rehn and Hebard) 

 DD. Vertex slender (long, but not as long as in lyristes), with ven- 

 tral surface narrowly but continuously margined latcrad and 

 distad with black. (Ovipositor much longer than caudal 



femur. Size medium, form slender.) ensiger (Harris) 



BB. Vertex moderately produced (for the genus), distinctl}- longer than 

 basal width, narrowing moderately or very weakly to apex (ex- 

 cept in typical robustus), which is arcuato-truncate (except in 

 typical robustus and to a less degree in robustus crepitans) . 

 C. Form robust. Pronotum not elongate, not expanding evenly cau- 

 dad. Ovipositor of normal width, long, slightly shorter than, to 

 (normally) slightly longer than, caudal femur. 



TRANS. AM. ENT. SOC, XL. 



