166 Mr. G. J. Arrow on the 



stridulating apparatus^ and I propose to put them together 

 in a new genus, to be called 



Metanastes, gen. nov. 



The typical species is M. australis, Fauvel, and to avoid 

 the double employment of the same name the later- described 

 Australian insect must be renamed M. blackburni. 



In the hitherto unknown male of M. australis the head 

 has a single (instead of paired) tubercle and a rather deep 

 pit behind it. No such sexual difference ia found in Hetero- 

 nychus, nor does it reappear in M. blackburni, but the females 

 of the two species are so much alike that it appears to me 

 impossible to separate them generically. In M. australis, 

 Fauvel, the elytra are rather more closely and irregularly 

 punctured than in M. blackburni, and the front tibiae are 

 simply tridentate, while in the latter there are one or two 

 minute secondary teeth. 



In the female of M. australis the pygidium is flat and in 

 the male very convex. 



The genus Euetheola was formed by Bates for the single 

 species Heteronychus humilis, Burm., the author comparing 

 it with Dyscinetus bidentatus, Burm. The latter insect, 

 although differing from E. humilis in the thickened front 

 tarsi of the male, is in other respects very closely allied to it. 

 It differs entirely from Dyscinetus in its toothed clypeus and 

 in the produced and exposed front part of the mandibles, as 

 well as in its general aspect. The alternative is presented 

 of transferring it to Euetheola or making another genus for 

 it, and for the present I prefer the former course. 



The following is a third closely related species : — 



Euetheola latipennis, sp. n. 



Nigra, nitida, elytris subopacis, brevis, postice lata, clypeo rugoso, 

 antice angusto, bidentato, a fronte carina angulata divisa, fronte 

 antice fortiter punctata, postice Isevi ; prothorace ubique grossis- 

 sime punctato, toto marginato, lateribus fortiter arcuatis ; 

 scutello punctato ; elytris baud profunda punctato-striatis, ad 

 marginem anticum rectis, ad humeros acute prominentibus, 

 postice dilatatis ; pygidio grosse et confluenter punctato ; corpore 

 subtus nigro, nitido, lateribus rugose punctatis ; tibiis anticis 

 fortiter et acute tridentatis : 



(S , tarsis anticis incrassatis, unguibus ingequalibua. 



Long. 13-14 mm. ; lat. max. 7*8 mm. 



Hab. Matto Grosso : Cuyaba; Paraguay: Sapucay. 



