MCNEILL REVISION OF THE TRUXALIN.^ OF NORTH AMERICA. 203 



Achurum acridodes, Stdl, 1873. Recen. Orth. , I, loi.. 

 Achurum acridodes, Thos., 1875. Rept. Geol. and Geog. Surv. W. 

 100 M., V, Zool., 865. 



Hab. Mexico. It is doubtful whether this species is distinct from 

 A. sumichrasti . I have not seen it. 



III. MERMIRIA, Stal. Fig. 3. 



The head is long, sometimes equaling the pronotum, with the top 

 slightly ascending, transversely moderately convex. Vertex horizontal, 

 triangular or semi-elliptical, convex but more or less sulcate near the 

 lateral carinas, which are more or less distinct, never sharp and high, 

 and which meet at an acute angle or are shortly or broadly rounded at 

 the apex. The median carina of the vertex is either slight, but mod- 

 erately distinct, or obsolete or entirely wanting. The lateral foveoLx 

 are usually indistinct elongate triangular or sub-lunar spaces without 

 distinct walls. The frontal costa is more or less completely sulcate 

 (frecjuently very deeply sulcate between the antennae) and strongly 

 prominent, with the sides acuminate above and sub-parallel below, 

 sometimes suddenly expanding and vanishing near the cl\peus. The 

 face, seen from the side, is straight or moderately or strongly sinuate 

 and strongly (female) or very strongly (male) declivent. The antennae 

 are strongly triquetrous and acuminate and ecjualing (female) or exceed- 

 ing considerably (male) the head and pronotum in length. The eyes 

 are long ovate or elliptical and are placed very obliquely. The pro- 

 notum is long with the disk a little elevated toward the median carina 

 which is distinct and cut once, more or less plainly, much behind the 

 middle. The lateral carina are rarely distinct, usually indistinct or 

 wanting, almost straight and parallel or very slightly divergent on the 

 metazone. The latter has the posterior margin nearly straight or very 

 obtusely angulate or gently rounded. The lateral lobes of the prono- 

 tum are vertical and parallel with both the anterior and posterior mar- 

 gins strongly oblique (the latter a little sinuate) and the lower margin 

 straight and in the same line with the lower border of the cheeks. 

 The presternum has a low quadrate bent spine. The mesosternal lobes 

 are separated by a space longer than broad (female) or are closed 

 (male); the metesternal lobes are closed entirely (male) or behind (fe- 

 male). The tegmina and wings are well developed, usually equaling 

 or exceeding the abdomen. The former have the scapular area a little 

 widened and transparent and somewhat regularly scalariform. The 



