402 PROCEEDINGS OF THE NATIONAL MUSEUM ^ol. in 



Platydema americanum Laporte and Brulle 



Plates 5 (Fig. 42) , 6 (Fig. 53) 



Platydema americana Laporte and Brull6, 1831, p. 358. 

 Platydema americanum Laporte and Brull^, Horn.— 1870, p. 383. 



Description. — Obovate, convex, reddish brown to almost black, 

 shining. Head moderately impressed between eyes, coarsely, densely 

 and irregularly punctm-ed, antennae and mouthparts reddish brown, 

 terminal segment of maxillary palpus elongate, narrowly triangular; 

 eyes large, flattened dorsally, usually separated by a distance sub- 

 equal to longer axis of one eye. Pronotum transverse, sides strongly 

 arcuate, converging rapidly from middle toward apex, lateral margin 

 broadly flattened, shghtly reflected, a broad depression slightly behind 

 middle, marginal bead fine, basal angles obtuse, apical angles broadly 

 rounded, punctures of disc fine and well separated, becoming larger 

 laterally, those of flattened portion of margins 3 or 4 times larger 

 than those of disc. Elytral striae feebly impressed, pimctm-es fine 

 and deep, intervals distinctly convex, finely, sparsely, but distinctly, 

 punctate; elytral margins rather broad, flaring, bead fine. Prosternal 

 process narrow, flattened, horizontal; metasternum rather coarsely 

 and densely punctured anteriorly, becoming more widely spaced pos- 

 teriorly and absent on caudal fourth; abdominal punctures fine me- 

 dially, becoming quite coarse and dense laterally, forming longi- 

 tudinal wrinldes ; apical segment uniformly finely and sparsely punctate. 

 Male genitaha with ventral portion of lateral lobes continued back- 

 ward as a single spine (pi. 4, fig. 25). No apparent external sex- 

 ual dimorphism. Measurements: length 4.6-7.2 mm.; width 2.6-3.8 

 mm. 



Remarks. — This species may be separated from all other members 

 of the species group by the pecuhar form of the pronotum. The 

 flattened and reflected, often crenulate lateral margins with the large 

 indentations just behind the middle, the accentuated impressions on 

 either side of the middle of the base, plus several other surface u-- 

 regularities combine to give the pronotum a very misshapen ap- 

 pearance. 



Type. — Not seen. The description leaves but Httle doubt as to 

 the identity of this species. As Laporte and BruUe point out: "La 

 tete .... marquee d'un enfoncement transversal entre les yeux 

 . . . . Le corselet ... est borde et un peu arrondi sur les cotes .... 

 et presente deux impressions en arriere et une autre, beaucoup moins 

 marquee, situee de chaque cote, vers le miUeu du bord lateral .... 

 La patrie .... est I'Amerique septentrionale." These excerpts from 

 the original description are suflScient to characterize the present species 

 to the exclusion of aU others. In coUections I find it frequently con- 



