MEBA]S*OPLU8. 167 



deeply grooved above the eye for the reception of the antennae, 

 which fold back into the groove and when so folded are invisible 

 from above ; mandibles stout, the masticatory margin armed with 

 4 teeth ; clypeus with the median portion broad, posteriorly 

 well defined, frontal area triangular, depressed, and at times 

 obscure ; autennal carinae short, very widely separated, continued 

 as lines along the upper border of the antennal groove ; antennae 

 of,moderate size and thickness, 9-jointed, the club distinct, formed 

 of the apical three joints ; eyes oval, always somewhat prominent. 

 Thorax above more or less square in form, the pro- and ineso- 

 notum with no vestige above of a suture between them, more 

 or less armed laterally and posteriorly with spines or teeth ; 

 metanotum depressed beneath the overhanging posterior portion 

 of the pro-mesonotal shield, vertical, armed at its upper or ante- 

 rior angles with two backward-pointing spines ; legs somewhat 

 short and stout, posterior tibiae with a single fine, simple, non- 

 pectinate calcar. Pedicel short, nodes large, sessile or only shortly 

 petiolate ; 1st node more or less conical ; 2nd globose, in some 

 species flattened anteriorly ; abdomen cordate, lightly concave in 

 front. 



$ . Differs from the in being larger, with a proportionately 

 smaller, rounder head, and immensely more massive, elongate, oval 

 abdomen. The antennae are 10-jointed, and the pro- and meso- 

 notum of the thorax are without spines ; fore wing with a large 

 radial, a long cubital, and a discoidal cell. 



d . Much smaller and slighter ; head with enormous eyes and 

 ocelli and 13-jointed antennae, the scape or 1st joint short, about 

 as long as the 2nd joint of the flagellum ; thorax without spines ; 

 pedicel long, nodes simply indicated by a cylindrical thickening ; 

 abdomen cordate. 



Key to the Species. 



A. Pro-niesonotal shield undivided and square, 



the four angles produced into very long and 



acute spines " M.mucronatw, p. 168. 



B. Pro-mesonotal shield undivided, but differ- 



ently armed. 



a. Mesonotum armed posteriorly with two long 



acute spines ; pronotum dentate M. bicolor, p. 168. 



b. Mesonotum armed posteriorly with only 



comparatively short teeth. 

 a'. Second node of pedicel with a medial 



tooth above pointing backwards M. belli, p. 169. 



b'. Second node of pedicel without such 



tooth, rounded posteriorly. 



a 2 . Abdomen finely reticulate, subopaque. M. rothneyi, p. 170. 

 b 2 . Abdomen highly polished, smooth, and 



shining M. Itevicentris, p. 170. 



