DYNASTIKLE 175 



doubtless exists in the male of both l&vipunctatus, of the Mexican 

 fauna, and dtibius, but was not mentioned by Mr. Bates. 



Parachalepus n. gen. 



I would suggest a distinct genus under the above name for certain 

 Dyscinetids, which are notably aberrant in pygidial structure, the 

 pygidium proper being rigidly united with the propygidium. 

 There are also two subgeneric groups here as follows: 



Pygidium almost of the usual length and densely hairy Group I 



Pygidium very short, glabrous, forming scarcely more than a broad 

 polished margin of the propygidium; head more developed. . Group II 



Species of both these groups seem to be much less numerous than 

 those of Dyscinetus. 



Group I. 



Subgenus Parachalepus in sp. 



This group comprises barbatus Fabr., hydrophiloides and luridus 

 of Burmeister, and the following: 



Form broadly elongate-oval, moderately convex, strongly shining, deep 

 black throughout, the legs not paler, the lustre sometimes slightly 

 greenish, especially in the male; head barely more than half as wide 

 as the prothorax, sparsely and extremely minutely punctulate, the 

 clypeus similarly and only a little more distinctly punctate, feebly 

 trapezoidal, twice as wide as long, the apex broadly sinuato-truncate, 

 with broadly rounded angles; entire edge margined with a broad 

 but feebly elevated bead, which, along the sides basally, flares out- 

 ward, becoming the crest of the anterior canthus of the eyes; suture 

 entire, very fine, feebly sinuate medially; prothorax three-fourths 

 or more wider than long, the sides slightly converging, evenly and 

 rather strongly arcuate, from the well rounded basal angles to the 

 acute apices; punctures sparse and very minute, becoming more 

 distinct laterally; scutellum sharply triangular, almost perfectly 

 smooth; elytra much wider than the prothorax, with very fine, 

 sparse, shallow, posteriorly open annular punctures, the double 

 series evident but not conspicuous, the entire surface smooth and 

 even; apex obliquely arcuately narrowed behind the middle to the 

 unusually narrowly rounded apex; side? broadly arcuate, strongly 

 arcuate and distinctly explanate and thickened medially in the 

 female, giving a rhomboidal aspect to the body; pygidia almost 

 completely covered by the elytra, the hairs of the propygidium very 

 long, 'yellow, those of the pygidium short, dense, the sculpture and 

 pubescence ending not very abruptly at a narrow glabrous shining 

 margin; hind tarsi slender, as long as the tibiae (cf ) or shorter (9 ). 

 Length ((^9) 19.8-20.5 mm.; width 10.0-11.2 mm. Brazil (Rio 

 Grande do Sul) *rhomboidalis n. sp. 



