Brazilian Baring 217 



Macrorevena n. gen. 



In this genus the body is rather large and stout, smooth, com- 

 pletely glabrous above and beneath and deep black in color. The 

 beak is subsimilar in the sexes, somewhat thick, rapidly tapering 

 distally, compressed, the flattened sides coarsely and rugosely 

 punctured; it is separated from the very convex head by a deep 

 reentrant angle, and its upper surface is evenly and strongly convex, 

 minutely and sparsely punctate; the sides of its concave under 

 surface are angulate near the base. The mandibles are rather 

 short and obtuse, not decussate but with not quite straight inner 

 margin, that of the right sinuate apically. Antennae submedial, 

 the very short scape coming very far from attaining the base, 

 rather slender, the first funicular joint nearly as long as the next 

 three, the second slightly elongate, the club very small, oval, not 

 as long as the preceding three joints, with large basal segment, 

 constituting fully half the mass. The anterior coxae are very 

 narrowly separated, the prosternum with short erect or obsolescent 

 spines, which are separated by a moderate or deep concavity or, 

 in the female, broadly and feebly concave and smooth, the flattened 

 part somewhat sharply limited at the sides and also having a small 

 deep polished pit at apex. The femora are feebly inflated, finely, 

 sparsely punctate, the hind tibiae normal in the female, but broadly 

 inflated with arcuate sides in the male, the claws slender, arcuate 

 and widely diverging. The thoracic apex is abruptly and strongly 

 tubulate, the constriction marked by a series of coarse punctures, 

 the basal angles rather obtusely rounded, the elytra with broadly 

 undulated surface, deep grooves and somewhat convex intervals. 

 The female abdomen is modified medio-basally, as well as that of 

 the male. 



As may be judged by the characters given above, this is a very 

 remarkable genus, especially in prosternal structure and in the 

 sexual characters of the hind legs and abdomen. There are three 

 species at hand as follows: 



Body less stout, the sides of the prothorax evenly and moderately arcuate, not 

 becoming quite parallel at base. Rhombic-suboval, convex, polished and 

 smooth; beak (cf ) rather thick, as long as the head and prothorax, feebly 

 arcuate, gradually more so basally, the antennae piceous; prothorax two- 

 fifths wider than long, the truncate tubulation but little more than two-fifths 

 as wide as the base; surface very minutely, remotely punctate, somewhat 

 more distinctly but not more closely at the sides, the basal lobe gradual, 

 strongly, evenly rounded, with convex and somewhat punctured apex, the 

 lateral impressions at base very feeble; scutellum smooth, half as wide at 

 base as at the truncate apex, the oblique sides strongly sinuate, the angles 

 acute and prominent; elytra almost a third longer than wide, a fourth wider 

 than the prothorax and much more than twice as long, evenly parabolic, 

 the humeri slightly prominent, the mes-epimera very distinct above in the" 

 reentrant angles; grooves deep, about a fourth as wide as the nearly smooth 



