McNeill — revision of the truxalin^ of north America. 215 



are not slender, they extend somewhat beyond the end of the abdo- 

 men. The valves of the ovipositor are but little exerted. 



This genus is represented in North America by a single species. It, 

 with Pcdeticitm, is a connecting link between Mermiria and Napaia 

 on the one side and Amphitoi-nus, Atkcnfetiis, and Erifettix upon the 

 other. 



Oxxcoryp/ii/s, Thos., 1873. Syn. Acrid. N. Am., 72. 



I. Opeia obscura, Thos. Fig. 7a, 7b, 7c. 



Oxycoryphus obscurus, Thos., 187 1. Pre. Rept. Surv. Mont., 446. 



Oxycoryphus obscuriis, Thos., 1873. Syn. Acrid. N. Am., 73. 



Oxycotyphus obsciinis, Bruner, 1883. 3rd Rept. U.S. Ent. Com , 55. 



Oxycoryphus obscurus, Bruner, 1885. Bui. Wash. Col. Lab. Nat. 

 Hist., T, No. 4, 130. 



Oxycoryphus obscurus, Bruner, 1885. Rept. Com. Agr. , 307. 



This is an extremely variable species in every way. The coloration 

 in particular is so variable that it is difficult to describe. In typical 

 specimens the dorsum is brown or green, nearly plain with sometimes 

 a streak of fuscous along the median carina. The sides are marked by 

 a stripe which extends backward from the eye, widening and generally 

 becoming more obscure. When most distinct, this stripe consists of 

 five parts, as follows : an upper streak of brown or fuscous below the 

 lateral carinas, below this a lighter streak followed by a white line, 

 and still below this the light and dark streak repeated. Apparently 

 these five elements of the lateral stripe may be varied in intensity of 

 coloration in any way so that the great dissimilarity in appearance is 

 produced. Nearly always, however, all these parts can be distinctly 

 or faintly seen, and in all cases the lower fifth of the pronotum at least 

 is brown. The tegmina have the discoidal area occupied by a row of 

 large usually distinct quadrate fuscous spots and the scapular area con- 

 tains a whitish streak. 



Hab. West of Missouri and Arkansas and east of the Rocky 

 Mountains. This seems to be a species peculiar to the great plains. 

 Its range is unusually great north and south, as it extends from the 

 northern to the southern boundaries of the United States and probably 

 much farther in each direction, while it is somewhat restricted east 

 and west. Bruner says it "occurs where the grasses are short and the 

 climate is arid," and reports it as common in the Yellowstone Valley. 

 The National Museum contains two females and one male which seem 



