164 MEMOIRS ON THE COLEOPTERA 



shorter and especially more slender, the club narrower; third joint not 

 over twice as long as wide; prothorax much shorter, twice as wide as long, 

 more parallel, the apex but little narrowed, the sides very evenly and 

 distinctly arcuate; elytra rather more narrowly rounded at apex. Length 

 (9) 2.9 mm.; width 1.35 mm. Missouri (near St. Louis). 



Triplax thoracica ssp. convergens nov. Form nearly as in antennata, 

 the coloration similar throughout; prothorax similar in length to that of 

 antennata, relatively longer than in thoracica, the elytra relatively 

 shorter than in that form of this very composite species; sculpture as in 

 antennata, the head however is not quite so large and the antennae a little 

 shorter; prothorax peculiar, about three-fifths wider than long, trapezoidal, 

 the long and rather conspicuously converging sides barely at all arcuate. 

 Length (cf) 4.3-4.8 mm.; width 2.0-2.3 mm. Michigan (Marquette), 

 Sherman. 



This subspecies is distinct in the trapezoidal prothorax; in an- 

 tennata this part of the body is less narrowed from base to apex and 

 the sides are always distinctly arcuate to subangulate. 



The following is of the thoracica type but is much shorter and 

 broader : 



Triplax latiuscula n. sp.- Broadly oblong-oval, convex, ferruginous, 

 with black elytra and piceous scutellum, the antennae black, gradually 

 pale basally; head large, much more than half as wide as the prothorax, 

 strongly and rather closely punctate, the eyes moderate in size, prominent; 

 antennae as long as the head and prothorax, the latter short, fully twice 

 as wide as long, behind the middle somewhat wider than at base, the sides 

 conspicuously arcuate, becoming more oblique anteriorly, with the apical 

 angles advanced and sharp, the foviferous thickening very small; base 

 broadly and strongly lobed medially; punctures rather coarse, deep and 

 close-set, smaller and sparser broadly toward the middle and narrowly near 

 the side margins; scutellum broadly angulate behind, almost punctureless; 

 elytra one-half longer than wide to somewhat less, as wide as the pro- 

 thorax, parallel, the sides broadly arcuate, circularly rounded in about 

 apical third; punctures strong and deep, rather close-set in scarcely at 

 all impressed series, the intervals with minute punctulation, generally 

 forming a very uneven single series; under surface more opaque, not very 

 coarsely but deeply and rather closely punctate throughout. Length 

 (9 ) 4.6-4.8 mm.; width 2.3-2.65 mm. Texas (the locality unrecorded). 

 Two examples. 



In comparing the type specimen of this species with the females 

 of thoracica, the body is at once perceived to be shorter, broader and 

 rather more closely and strongly punctate, but to differ especially 

 by the short and laterally subinflated prothorax, with very strongly 

 arcuate sides; there can be little doubt that it constitutes a distinct 

 species. 



