408 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 117 



just above clypeus, antennae and mouthparts reddish brown, terminal 

 segment of maxillary palpus short, broadly triangular ; eyes small, con- 

 vex dorsally, inner margins raised well above plane of head, separated 

 ventrally by a distance subequal to twice the longer axis of one eye. 

 Pronotum transverse, sides rather strongly arcuate, parallel at least 

 behind middle, basal angles obtusely rectangular, apical angles 

 broadly rounded, lateral marginal bead fine, margins slightly and uni- 

 formly flattened from base to apex, often feebly reflected, surface 

 finely and sparsely punctured on disc with larger punctures in lateral 

 depression. Elytral striae shallov/ly but distinctly impressed, punc- 

 tures coarse and well separated, intervals more or less strongly convex, 

 minutely and sparsely punctate. Prosternal process broad and flat 

 between coxae, its apex usually prominent but occasionally deflected 

 and obtuse. Ventral surface of pronotum usually impunctate but 

 frequently with feeble longitudinal ridges. Metasternum coarsely 

 but sparsely punctured; abdominal sternites coarsely and densely 

 punctured except apical two which have minute, mdely separated 

 punctures. Male genitalia with ventral portions of lateral lobes 

 continued backward as two short spines (pi. 4, fig. 29). No apparent 

 sexual dimorphism. Measurements: length 4.4 — 6.3mm. ; width 2.4 — 

 3.5 mm. 



Remarks. — This species closely approaches P. subcostatum in 

 general appearance and understandably is often mistaken for it in 

 collections. The majority of specimens may be separated from 

 P. subcostatum, at once by the erect prosternal process; however, a 

 number have been observed in which the apex of this structure is 

 concealed in such a way that it v»^ould be impossible to identify them 

 by this character alone, without relaxing them and pushing back 

 the pronotum in order to raise the prosternum from its cleft in 

 the mesosternura. A number of other constant but unfortunately 

 relative characters render it quite distinct from P. subcostatum. 

 The duller lustre of the dorsum, the shape of the pronotum and the 

 deeper, more coarsely punctured elytral striae are useful taxonomic 

 characters, although difficult to describe. The elytral intervals of 

 P. laevipes are always distinctly convex and obscurely punctured. 

 The male genitalia are of little or no value in diagnosing this species. 



Platydema crenatum LeConte is but an extreme variant of the 

 present species, in which the punctures of the elytral striae are slightly 

 coarser and the intervals more convex. 



Type. — AICZ 8371. The specimen bearing the type label is spotted 

 with mud or other detritus, but is otherwise in good condition and 

 quite recognizable. It bears a pink 'Middle States" label. Other 

 material under this name in the LeConte collection (MCZ) where 

 the type now reposes includes two additional specimens with the pink 



