On Aquatic Carnivorous Coleoptera or Dytiscidce. 545 



ad angulos posteriores subsinuato, his acutis, margine lateral! sat lato ; prosterni 

 processu lato, piano, apice obtuso. Long. 7i, lat. 42 m.m. 



The two individuals I have seen of this species are in very bad condition, and I 

 do not know their sex ; they bear a great resemblance to some of the varieties of 

 Dytiscus decempmictatus (No. 763), but may be readily distinguished by the blunt 

 point of the prosternal process ; the sculpture of the upper surface is excessively 

 dense and fine, but prevents the appearance of its being polished ; the subserial 

 punctures of the elytra although fine are quite easily distinguished. 



South America, (interior of Brazil). 828. 



770. Agabus nigerrimus, Aube, M.C. — Rotuudato-ovalis, latus, subdepressus, 

 supra densissime subtilissimeque reticulatus, nitidus, niger, antennis pedibusque 

 rufis, capite in medio rufo-maculato ; thorace vix ad angulos anteriores rutescente, 

 basi utrinque vix sinuato, angulis po.sterioribus subacutis, margine laterali sat lato ; 

 elytris maculis duabus minutis, sublateralibus testaceis, una pone medium altera ad 

 apicem; prosterni processu lato, piano, apice obtuso. Long. 74, lat. 4^ m.m. 



I have seen only a single individual, in very bad condition, of this species ; though 

 closely allied to P. ornatifrons, it is easily distinguished by its broader form. The 

 specimen is a male, its front and middle tarsi are scarcely incrassate, but the basal 

 joints are furnished beneath with dense short hairs ; the apical ventral segment is 

 quite smooth. 



South America, (Brazil, coll. de Bonvouloii-). 829. 



771. Platynectes parananus, n. sp. — Rotundato-ovalis, latus, minus depressus 

 subkevigatus, nitidus, niger, ventre rufescente, antennis pedibusque rufis, capite in 

 medio thoraceque ad angulos anteriores testaceo-maculatis ; elytris maculis tribus 

 parvulis sublateralibus testaceis ; thorace basi utrinque baud sinuato, angulis pos- 

 terioribus sat acutis, margine laterali fere tenui ; prosterni processu lato, piano, 

 apice obtuso. Long. 7i, lat. 5 m,m. 



This species is excessively remarkable by its broad form ; the front legs are more 

 widely distant than usual in the allies, so that the prosternal process appears less 

 abruptly dilated : the sculpture of the upper surface is excessively dense and fine, 

 even the serial punctures being nearly effaced ; the only individual I have seen is a 

 male, but has lost its front tarsi, the middle ones however are rather broadly clothed 

 beneath with short hairs bearing distinct small narrow palettes. 



South America, (Parana). 830. 



