| A new species of Polycentrusis described from the rio Negro, in Brazil. It is distinguished from P. schomburgkii by the presence of two dark postocular and one subocular band, all smaller than orbital diameter, blunt snout, isognathous mouth, reduction of the serrations on the lower edge of the lacrimal-spines ranging from zero to two tiny spines at the posterior end, intensely serrated edge of the interopercle, fully serrated posterior edge of the vertical arm of the preopercle, presence of five pungent opercular spines, subopercle broadly serrated along most of its posterior ventral edge, presence of serrations dorsally on the posterior margin of the cleithrum, fourth ray of pectoral fin reaching the vertical through the anal-fin origin, 19-21 predorsal... |
