A new genus, Cryptophyllobates, was recently described for a species of dendrobatid that was originally described as Phyllobates azureiventris. One of the distinguishing characters of this frog is the presence of dorsolateral stripes that end on the posterior back above the thighs. While conducting fieldwork in Acre, Brazil, I collected an unusual dendrobatid that transported all tadpoles in a clutch at one time; however, tadpoles of this species were more similar to Dendrobates than to Epipedobates. I subsequently discovered that this species is similar to Cryptophyllobates azureiventris and herein describe it as the second species in this genus. Molecular studies indicated that the new species and C. azureiventris are sister species and that they are closely related to some clades of Colostethus. Courtship of the new species was not observed, but tadpoles were found in a pool in a fallen tree, and adults were frequently seen in treefall gaps. Tadpoles are similar to those of Dendrobates in that they are predaceous, possibly as a result of convergence in behavior in response to development in similar restricted microhabitats.