368 STUDIES IN AMERICAN TETTIGONIIDAE (oRTHOPTERa) 



in males from the same series. The shape and venation of 

 the stridulating field of the male tegmen shows distinctive char- 

 acters in almost every species, but these differences are often very 

 difficult to define and are ill suited for use in a key, though in com- 

 parison of material their presence is readily noted. The genic- 

 ular lobes of all the species under consideration are unispinose. 

 The spination of the limbs shows decided variability and is of 

 interest only in showing somewhat greater development or aver- 

 age greater number of spines in some species than in others; very 

 small but conspicuous dark markings on the ventral margins of 

 the caudal femora immediately under the spines are found in N'. 

 palustris, often in triops and sometimes present though weakl}^ 

 defined in retusus. In some species minor characters are to be 

 found in the male genitalia; in the supra-anal plate of exilisca- 

 norus; in the cerci of retusus and triops, and the styles of the 

 subgenital plate are decidedly longer in velox, palustris, retusus 

 and triops than in the other species studied. The ovipositor 

 shows a greater upward curvature in exiliscanorus and retusiis 

 than in the other species here considered; it shows a distinct 

 downward curvature in lyristes and to a less extent in melano- 

 rhinus; it is rather wider than usual in exiliscanorus, melanorhinus, 

 lyristes and palustris, and in the three latter species, and particu- 

 larly in palustris, the widening being more decided meso-distad. 



Biological Notes. — The junior author has studied the song and 

 habits of all of the species here treated excepting N. nebrascensis, 

 and an opportunity to compare at the same time, or at least on 

 the same day, A^. exiliscanorus, melanorhinus, lyristes, robustus 

 robustus, caudellianus, palustris and retusus in New Jersey during 

 the summer of 1914, has been of decided assistance. The species 

 either sing with a continuous buzzing or with a succession of brief 

 buzzing notes; to this latter class belong C. exiliscanorus, ensiger 

 and caudellianus. 



The species under consideration are all more or less vagrant 

 at times. The distance to which they may wander is problemati- 

 cal but in some cases probably considerable. The records of N . 

 exiliscanorus from New Harmony, Indiana, Thompson's Mills, 

 Georgia, and Dallas, Texas, are very possibly due to individuals 

 having strayed long distances from their normal area of distribu- 

 tion, at least this is highly probable for the first two records which 



