2 20 DAVENPORT ACADEMY OF NATURAL SCIENCES. 



reference. I am unacquainted with the species, but I think that it is 

 probable that it is synonomous with virgatus. 



6. Eritettix xaviculus, Scud. 



GomphoceJiis navicula, Scud., 1876. U. S. Geol. Surv. W. 100 

 Mer., App. JJ., 506. 



GompJiocerus navicula, Bruner, 1883. 3rd. Rept. Ent. Com., 56. 



Hab. Southern Colorado, Northern New Mexico, Montana. The 

 National Museum contains Scudder's type from Southern Colorado, 

 and another specimen from Montana. The latter does not agree 

 closely with the type, but the divergence is no greater than should be 

 expected in species so variable as the Eritettix. 



7. Eritettix abortivus, Bruner. 



Eritettix abortiiuis, Bruner, 1889. Proc. U. S. Nat. Mus. , 56, pi. 

 i, figs. 8 and 9. 



Hab. Central Texas (Schaupp), Washington Co., Tex. (Bruner). 

 This species is most nearly related to navicuhis, but it is easily distin- 

 guished from that by its abortive tegmina and wings, its smaller size 

 and very heavy and short antennae. 



X. SYRBULA, Stal. Fig. 10. 



Head not much shorter than the pronotum with the occiput moder- 

 ately rounded transversely, and slightly or considerably ascending. 

 Vertex co^ivex and more or less sulcate, horizontal and semi-elliptical 

 or sub-triangular in shape with a distinct median carina not less ap- 

 parent than the lateral carina;, which are suddenly curved inward a 

 short distance back of the anterior margin of the eye, and from that 

 point together with the median carina are more or less distinctly con- 

 tinued to the pronotum. The lateral feveolae, generally indistinct and 

 small, are triangular in shape and invisible from above. The frontal 

 costa is plain, a little convex or more or less sulcate, continued to or 

 even upon the clypeus, decidedly constricted at the apex and very 

 slightly at the ocellus. The antennae are flattened decidedly at the 

 base and distinctly acuminate (female) or are flattened moderately at the 

 base and decidedly or strongly expanded apically and acuminate 

 (male). The pronotum has the disk plain with the three carinae dis- 

 tinct, the lateral being gently or strongly sinuate and very slightly or 

 moderately divergent posteriorly. All are severed by a single sulcus 



