REHN AND HEBARD 39 



Transition and portions of the Canadian life zones, glaberrimum 

 is chiefly restricted to the Austroriparian zone. The ranges 

 of the two touch and possibly to a slight degree overlap, but 

 there is no definite intergradation of the material, typical indi- 

 viduals of each occurring side by side at certain localities on the 

 meeting ground of the two species. 



The great difficulty in the past with these two names {i. e., 

 glaberrimum and vulgare) has been due to the failure of authors 

 to comprehend the real characters separating them. Large 

 specimens of vulgare and individuals of the same with caudate 

 tegmina and wings were called glaberrimum regardless of the 

 good structural characters which separate the two. All the 

 glaberrimum records from the normal range of vulgare are pro- 

 bably these long-winged vulgare, but those records from the line 

 where the species meet cannot be assigned without examination 

 of the original material. 



The general characters separating the two species are; the 

 generally larger, frequently much larger, size of glaberrimum, the 

 relatively broader and shallower fastigium of the same form, the 

 broader lateral lobes of the pronotum of vulgare, the generallj^more 

 elongate speculum of the stridulating field of the male tegmina 

 of glaberrimum, the preapical node on the dorsal surface of the 

 male cercus in vulgare, this being absent in glaberriuium, and the 

 straighter and less falcate ovipositor of the female of glaberrimum. 



In general size vulgare holds rather small northward, material 

 from the more southern localities averaging larger, this being 

 quite noticeable in specimens from North Carolina, Missouri, 

 south-central Kansas, Oklahoma and Texas localities. However, 

 like the other forms of this genus, individual variation at any 

 one place is very considerable, and in series averaging large we 

 will find small or medium sized individuals and vice versa. In 

 no case, however, does this species reach the great size frequently 

 attained by glaberrimum. 



Individuals with elongate tegmina and wings, i. e., these very 

 considerably exceeding the tips of the caudal femora, occur in 

 the material before us from all over the range of the species. The 

 localities represented by this phase in the series before us are: 

 North Saugus and Seekonk, Massachusetts; Port Allegany and 

 Rockville, Pennsylvania; Delaware; Chestertown, Maryland; 



PEANS. AM. ENT. SOC, XLI. 



