20 STUDIES IN AMERICAN TETTIGONIIDAE (oRTHOPTERA) 



The species of this genus fall. into nine groups, which appear to 

 be natural in character. One of these groups forms the new sub- 

 genus Stenorhoptrum, two constitute the other new subgenus 

 Metarhoptrum and the remainder can be assembled under the 

 restricted subgenus Orchelimum. The chief criteria which we 

 have used in delimiting these groups are the number of caudal 

 genicular spines and the general form of the male cercus, but we 

 have also taken into consideration other features, as the form of 

 the ovipositor of the female, form and general character of the 

 stridulating field of the male tegmina, the form of the lateral 

 lobes of the pronotum and the general build. 



This group arrangement is as follows: 



Orchelimum s. s. 



Group A. (agile) 

 Cerci with simple, Ovipositor falcate. Stridulating field 

 rect-divergeiit me- of male tegmen 



dian tooth. normal. 



Lateral lobes with 

 deeply and broad- 

 ly indicated hu- 

 meral sinus. 



Group B. (glaberrimum, vulgare, gladiator, calcaralum) 



Cerci with simple 

 to produced rect- 

 divergent or sub- 

 falcate (distad) 

 median tooth. 



Ovipositor falcate 

 or with nearly 

 straight dorsal 

 outline, occasion- 

 ally very deep. 



Stridulating field 

 normal, but large 

 proportionately. 



Lateral lobes 

 broad, with well 

 indicated and 

 broad to but little 

 indicated humeral 

 sinus. 



Cerci heavy, cari- 

 nate dorsad, with 

 median tooth di- 

 rected more or less 

 strongly p r o x i- 

 mad. 



Group C. {hidlatum, lalicauda, nigripes) 

 Ovipositor strong- Stridulating field 

 ly falcate, broader normal but broad, 

 mesad than proxi- 

 mad. 



Lateral lobes with 

 humeral sinus 

 hardly indicated, 

 ventrad of same 

 caudal margin is 

 httle arcuate. 



Group D. (minor) 



Cerci much as in Ovipositor falcate, Stridulating field Lateral lobes 



group C but more long, broad and normal but broad, broad with well in- 



incrassate and less heavy. dicated and broad 



carinate. humeral sinus. 



