540 Coleopterological Notices, IV. 



MADARELLIS n. gen. 



A series of Gonoproctus quad?'ipustulatus Fab. (quadriplagiatus 

 Lac.), taken by Mr. H. H. Smith on the Amazon near Santarem, 

 shows clearly that Lacordaire's type of Conoproctus is the male. 

 In the female the form, sculpture and coloration throughout are 

 similar, but the beak is not so long, more arcuate and tapering, with 

 the antennae shorter and inserted near the middle, the pygidium 

 being broadly rounded, oblique and perfectly normal. These sexual 

 differences are extraordinary, but are evinced in an unmistakably 

 parallel and, as far as the beak is concerned, almost equally striking 

 manner in another Brazilian species, from the same collection and 

 not yet identified, but which, from its general habitus and simple 

 male pygidium, must be assigned to Madarus. Finally, in Madarus 

 biplagiatus, which I also have before me, the same sexual differences 

 are observable but to a very slight degree, the antennae being in- 

 serted near apical third in the male and just beyond the middle in 

 the somewhat shorter beak of the female; quadripustulatus is how- 

 ever the only species in which the pygidium is affected sexually. 



It is quite evident, therefore, that biplagiatus and quadripustu- 

 latus must be placed in the same genus, and I would suggest that 

 these species be included under the name Conoproctus Lac, and 

 that the name Madarus Sch. be reserved for those species mentioned 

 by Lacordaire (Gen. Col., YJI, p. 257), as forming a second section 

 of Madarus, and having as types vorticosus and migrator. Both 

 Conoproctus and Madarus, as thus limited, have the femora un- 

 armed, and I have here proposed the genus Madarellus, to include 

 those species having the prothorax short, broad, very abruptly 

 and strongly constricted at apex, and the femora armed beneath 

 with a minute spiculiform denticle. It differs further from Cono- 

 proctus in having the posterior lobe of the prosternum broadly 

 emarginate or subtransverse, with the lateral angles acute and not 

 broadly rounded as in that genus, in having a post-apical prosternal 

 fovea with short parallel folds of the surface, and a small triangular 

 scutellum, truncate at base and not large, short and broadly lunate 

 as in Conoproctus. The anterior coxae, it should be added, are 

 much more remote and rather smaller than in the latter genus. 



In Madarellus the beak is about one-half as long as the body in 

 the female, evenly, distinctly arcuate, slender, the impression sepa- 

 rating it from the head being almost completely obsolete and the 



