54 OETHOPTEEA. 



[3. Eritettix navicula, Scudd. 



Gomphocerus navicula, Scudd. Ann. Rep. Chief Eng. 1875, pp. 506, 507 (1876) *; Bruner, Rep. 



U.S. Ent. Comm. iii. p. 56 (1883) \ 

 Eritettix navicula, McNeill, Proc. Dav. Acad. Nat. Sci. vi. pp. 218-220 (1897) 3 . 



Eab. Noeth Ameeiga, plains east of the Rocky Mountains 1_3 . 



Being an early spring insect, this locust has escaped most collectors, who generally 

 visit the region during the summer and autumn. It should also occur on the grassy 

 plains and tablelands of Northern Mexico.] 



[4. Eritettix variabilis, Bruner. 



Eritettix variabilis, Bruner, Proc. U.S. Nat. Mus. xii. p. 56 (1890) 1 ; McNeill, Proc. Dav. Acad. 



Nat. Sci. vi. p. 219 (1897) 2 . 

 Opeia obscura, Scudd. & Ckll. Proc. Dav. Acad. Nat. Sci. ix. p. 25 (1902) (part.) \ 



Hab. Noeth Ameeica, Silver City, New Mexico 1-3 . 



This species certainly occurs a little farther south across the Mexican border. The 

 types were collected by Mr. Marsh in May. For some unaccountable reason, Scudder 

 and Cockerell have mistaken JE. variabilis for the very common Opeia obscura, Thomas, 

 which inhabits the plains-region from the Mexican boundary to the Saskatchewan 

 River.] 



[EUPEDETES, Scudder. 

 Eupedetes, Scudder, Proc. Dav. Acad. Nat. Sci. ix. pp. 24, 25 (1902). 



This is another genus which has been characterized since the synopsis of genera 

 (antea, pp. 26-34) was prepared. As it also occurs in a region well represented by forms 

 belonging to the fauna of Mexico, I have thought it best to include it herewith as a 

 footnote *.] 



[MESOCHLOA, Scudder. 



Eritettix, Bruner, Proc. U.S. Nat. Mus. xii. p. 56 (1890) (part.) ; McNeill, Proc. Dav. Acad. Nat. 



Sci. vi. p. 217 (1897). 

 Mesochloa, Scudder, Psyche, viii. pp. 234, 239 (1898). 



* EUPEDETES, Scudder. 



" Of small size, compact, compressed. Head distinctly shorter than pronotum, in no way ascending, briefly 

 truncate apically, the face considerably oblique ; vertex with dorsal and approximate subdorsal rather 

 coarse carinations. Eastigium extending beyond eyes as far as its basal breadth, apically rectangulate, 

 but a little truncate ; lateral foveolse invisible from above, minute, trigonal ; frontal costa narrow, plane, 

 subequal, but expanding below the ocellus ; eyes parallel to front, subelliptical, moderate ; antennae a 

 little longer than the head and prothorax together, filiform, not slender, scarcely depressed. Pronotum 

 rather short, nearly uniform, the lateral carina? a little incurved in the middle, the median carina accom- 

 panied by a pair of supplementary median carina?, the front margin truncate, the hind margin broadly 

 obtusangulate ; mesosternal lobes separated by a rather wide space, broader than long. Tegmina and 



