On Aquatic Carnivorous Coleoptera or Dytiscide. 545 
ad angulos posteriores subsinuato, his acutis, margine laterali sat lato ; prosterni 
processu lato, plano, apice obtuso. Long. 73, lat. 44 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 decempunctatus (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 finc, 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, Aubé, M.C.—Rotundato-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 posterioribus subacutis, margine laterali sat lato ; 
elytris maculis duabus minutis, sublateralibus testaceis, una pone medium altera ad 
apicem ; prosterni processu lato, plano, apice obtuso. Long. 7}, lat. 44 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 Bonvouloir), 829, 
_ 771. Platynectes parananus, n. sp.—Rotundato-ovalis, latus, minus depressus 
subleevigatus, 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 haud sinuato, angulis pos- 
terioribus sat acutis, margine laterali fere tenui; prosterni processu lato, plano, 
apice obtuso. Long. 73, 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. 
