160 NORTH AMERICAN MELANOPLI (ORTHOPTERA) 



tionships. This latter situation is quite different from that 

 which is shown by the species and races of the evidently more 

 plastic Saltator Group here discussed in Part X. 



All of the five species invariably have pink caudal tibiae in 

 both sexes. All are sylvan or are present in the open where 

 usually characteristically sylvan ground cover occurs, such as 

 huckleberry bushes, Sweet Fern, Sheep Laurel and forest grasses. 

 All are found in the Appalachian Mountains, mancus being 

 further widely locally distributed in New England and south- 

 eastern Canada, islandicus in the central portion of the northern 

 United States and southern Canada and celatus in the adjacent 

 plateaus and mountains of Tennessee (and probably Kentucky). 



Females are indistinguishable or separable only on subtile 

 characters or average slight differences which could be treated 

 only at considerable length and might even then be misleading. 

 The following key is therefore furnished to distinguish only males. 



1. Cercus with ventral margin (rounded rect- to obtuse) angulate produced 



mesad. Penis distinctive (with shaft short and thick, the intricately 



specialized projections large) 5. diver gens Morse 



Cercus with ventral margin not produced mesad 2 



2. Cercus with apex faintly to definitely spatulate. Penis with shaft short 



and thick 3 



Cercus not enlarged distad. Penis with shaft more elongate and more 

 slender 4 



3. Penis with shaft short and thick, simple; the intricately specialized 



projections small. Cercus moderately elongate and moderately broad 



with apex faintly to definitely spatulate) 1. mancus (Smith) 



Penis with shaft short and very thick with distal portions cephalad 

 produced in two adjacent cochleate lobes the margins of which are 

 very finely and evenly serrulate. Cercus rather short and stout with 

 apex definitely spatulate 4. serrulatus new species 



4. Penis with shaft very elongate and very slender, the sheath extending 



equally far distad on all sides, the intricately specialized distal pro- 

 jections smaller. Cercus normally moderately elongate and narrow 

 at apex, varying to (rarely) rather short and (rarely in West, much 

 more frequently in parts of East) with apex conspicuously broader. 



2. islandicus Blatchley 

 Penis with shaft not as elongate and heavier, the sheath leaving much 

 more of the ectoparameres exposed in caudal aspect, the intricately 

 specialized distal projections larger. Cercus normally elongate and 

 very narrow at apex, varying to shorter and with apex conspicuously 

 broader 3. celatus Morse 



