OPEIA. 59 



streaked with brown and black. Discal field of tegmina furnished 



with a row of dark brown or black spots [1. obscura, Thorn.] 



b % . General colour uniformly light testaceous. Discal field of tegmina 

 concolorous. 

 c 1 . Lateral carinse of the pronotum gently approaching in front, the 



last transverse sulcus scarcely visible 3. pallida, sp. n. 



c\ Lateral carinse of the pronotum parallel, the last transverse sulcus 



distinct [4. testacea, Scudd.] 



A 2 . Tegmina abbreviated, seldom more than half the length of the abdomen 

 in the female, a trifle longer in the male, generally acuminate. 

 b 1 . More slender. The pronotum about as wide in front as behind. 

 Median carina of vertex prominent even on occiput. Tegmina often 



with much green 2, imperfecta, sp. n. 



b*. More robust. The pronotum slightly broadest behind. Median 

 carina of vertex disappearing on the occiput. 

 c x . Smaller. Less varied with dark and light stripes. Tegmina touch- 

 ing or overlapping above. 

 d 1 . Lateral carinse of the pronotum gently sinuate, the anterior lobe 

 constricted both at the sides and at a little behind the anterior 

 margin above. Tegmina of the female just touching above . 5. mexicana, sp. n. 

 d 2 . Lateral carinse of the pronotum straight, the anterior lobe not 



constricted. Tegmina of the female slightly overlapping above. 6. palmeri, sp. n. 

 c\ Larger. Much varied with dark and light stripes. Tegmina not 



quite touching above 7. lineata, sp. n. 



[1. Opeia Obscura, Thomas. 

 Oxycoryphus obscurus, Thomas, Rep. U.S. Geol. Surv. Mont. p. 446 (1871) l ; Syn. Acrid. N. Amer. 



p. 73 (1873) 2 . 

 Opeia obscura, McNeill, Proc. Dav. Acad. Nat. Sci. vi. pp. 215, 216, t. 2. figg. 7, 7 a,b,c (1897) 3 ; 



Scudd. Proc. Amer. Acad. Arts & Sci. xxxv. p. 45 (1899) \ 



Hab. Noeth America 1_4 , Plains-regions of the Saskatchewan River, Texas, New 

 Mexico, Arizona. 



By far the most widely distributed species of the genus. Although not represented 

 in the collections coming from south of the Mexican boundary, it is known to occur 

 abundantly in the adjacent regions to the north, and it is quite probable, therefore, 

 that it inhabits portions of Northern Mexico as well.] 



2. Opeia imperfecta, sp. n. 



Yery similar in size, colour, and general appearance to 0. obscura, but with abbreviated tegmina and wings. 

 It also differs from that insect in its somewhat more slender form, slightly longer pronotum, the 

 more advanced vertex, and rather strongly sloping face. The frontal costa is a little wider above the 

 ocellus in 0. imperfecta than in 0. obscura, and has its walls sharper and more nearly parallel. The 

 pronotum of the female has its lateral carinas nearly or quite as widely separated in front as behind, while 

 in this sex of 0. obscura they perceptibly converge anteriorly. The tegmina and wings of 0. imperfecta 



Ii 2 



