Platynin^ 19 



Trapezodera n. gen. 



There are a number of species placed under Colpodes by Bates, 

 which differ greatly from the normal American forms in the trape- 

 zoidal outline of the prothorax; this imparts to them a peculiarity 

 of facies which is very striking. I have selected as typical of these, 

 a species described by Mr. Bates under the name Colpodes cenei- 

 caiida, but it appears that Colpodes ignicauda, hemicydicus and 

 perhaps some others, will also have to be included. Still other 

 genera may have to be formed for species included under Colpodes 

 by Mr. Bates, especially such as stricticollis , pterostichoides and 

 dyschirioides. 



In Trapezodera, as represented by ceneicauda, the hind wings, 

 instead of being absent or vestigial as in all the preceding genera, 

 are well developed, and the slender antennae have the third and 

 fourth joints equal. The sides of the pronotum are widely reflexed, 

 with the upturned basal angles evident though rather obtuse. 

 The hind body is much wider than the anterior parts and oblong- 

 oval, with more rapidly rounded humeri, distinct oblique apical 

 sinus and longer deep scutellar stria. The met-episterna are 

 notably elongate and the fourth anterior male tarsal joint is oval, 

 with the fifth attached dorsally rather behind the middle, the sloping 

 concavity having lobe-like prominent sides but with the apex 

 apparently truncate; the preceding joints have two rows of inclined 

 gelatinous plates. The mentum tooth is narrow, rounded at tip. 

 The type may be described as follows: 



Body oblong-suboval, rather strongly convex, piceo-rufous, the elytra 

 darker and with greenish-metallic lustre, highly polished; under 

 surface and legs rufous; head slightly elongate, two-thirds as wide 

 as the prothorax, with very short tempora, the eyes well developed 

 and prominent; antennae very slender, slightly more than half as 

 long as the body; prothorax nearly a fourth wider than long, widest 

 far behind the middle, the sides feebly arcuate; base transverse, 

 much wider than the apex and just visibly narrower than at basal 

 third; apex feebly sinuate, with broadly rounded angles; sides 

 broadly reflexed, still more widely toward base, the angles obtuse; 

 surface with fine and feeble transverse rugulae, moderate smooth 

 concave foveae and finely impressed stria, the transverse impressions 

 very feeble; elytra three-fifths longer than wide, twice as wide as 

 the prothorax, the sides subparallel, feebly arcuate except basally 

 and apically; striae not fine, smooth, moderately deep; intervals 

 nearly flat, the third with three punctures, the first adhering to the 



