Three new species of fossil aphids are described from Canadian amber, age the Upper Cretaceous, viz. Longiradius foottitti n. gen. et n. sp., which has been referred to Palaeoaphididae, Canaphis albertensis n. gen. et n. sp. and Aphidinius constrictus n. gen. et n. sp., which have been impossible to place in any known family. Furthermore more material of Mesozoicaphis canadensis Heie, belonging to the extinct family Mesozoicaphididae, are described. At least 32 specimens of Mesozoicaphis spp. occur in the material, often more than two in the same piece of amber, making it highly probable that their host plant was the resin-producing gymnosperm. Eight new species of fossil aphids with 16 specimens are described from clay shales in Nevada, age the Middle Miocene, viz. Palaeogreenidea rittae n. gen. et n. sp. belonging to the family Greenideidae, Similidrepan pulawskii n. gen. et n. sp., Nevaphis nevadensis n. gen. et n. sp. and Americaphis longipes n. gen. et n. sp., which have placed in Drepanosiphidae, Lachnarius miocaenicus n. gen. et n. sp., which belongs to Lachnidae, and Eriosaphis leei gen. et n. sp., Eriosomaphis jesperi n. gen. et n. sp. and Eriosomaphis occidentalis n. sp., which have been placed in Eriosomatidae (= Pemphigidae).