IOWA ACADEMY OF SCIENCES. 39 



B. Thorax roundingly six-angular, posterior margin round- 

 ing, with a slight medianexcavation. Vertex longitud- 

 inally furrowed. Claval veins distant '^.Aulacizes. 



BB. Thorax 4-angular, posterior margin broadly, roundingly 

 emarginate, the anterior and posterior margins nearly 

 parallel. Claval veins often united in the middle or 

 approaching and tied by a cross nervure. 

 C. Vertex long, triangular, longer than width 

 between eyes side margins nearly straight, face as 



seen from side nearly straight Homalodisca.^ 



CC Vertex obtusely rounding, shorter or only equal 

 to width between eyes, face as seen from side 



roundingly angled Oncometopia.cy 



Kk. Ledge above antenna! sockets small, the anterior extremity 

 as seen from above not projecting, included in the curve of 

 the head, Anterior tibiae slender round or triangular, Elytra 

 broad, covering the abdominal tergum. Head and pronotum 

 rarely sloping. 



B. Elytra not reticulate veined at the apex, at most with 

 five apical and three anteapical cells. Head not greatly 

 produced. 



C. Vertex with the margin rounding obtuse, the 

 front inflated. 



D. Antennae setaceous, pronotum not twice 

 as long as scutellum the posterior margin 

 long not strongly emarginate ..Tettigonia. o 

 DD. Antennae in the male enlarged at the apex. 

 Pronotum less than twice as long as the 

 scutellum, posterior margin short deeply 



emarginate Helochara.'^ 



CC. Vertex flat, the margin sharp or line-marked, 

 distinct, vertex and front forming an acute angle, 

 front broadly transversely convex, not inflated... 



Diedrocephala . o 



BB. Elytra reticulate veined from the apex as far back as 

 the forking of the outer branch of the first sector. Head 

 often produced into a triangle, longer than pronotum.. 

 Draeculacephala.o 



O GENUS AULACIZES AM. AND SERV. 

 Head slightly inclined, vertex moderately long, bluntly round- 

 ing disc, nearly flat longitudinally, furrowed front gibbous, clypeus 

 as seen from side obtusely angled, a distinct ledge over antennal 

 sockets, pronotum inclined anteriorly long, 6-angular widest at the 

 lateral angles, rounding behind with a slight median emargination 

 as in Tettigonia, anterior tibite furrowed on upv>er side, elytra not 

 concealing lateral margin of abdomen. 



But one species of this genus lias been found in the 

 United States. 



