Notes on Paleozoic Malacostraca of USSR. Pygocephalomorpha

The classification of higher crustacea is reviewed and the family Tealliocaridae is considered to be a synonym of Pygocephalidae of the order PygocephalOmorpha. Hitherto only two representatives of Paleozoic higher crustacea have been known from the USSR. A new genus and species of pygocephalid, Brooksocaris aisenvergi, is described from the Carboniferous of the Ukraine, and another unnamed form from the Devonian of Kaluga is reported. Burkenroad's (1963) hypothesis of a polyphyletic origin of the Pygocephalomorpha is rejected. Based on material now available, the order is regarded as a single, natural grouping, the ancestors and progeny of which cannot for the moment be confidently identified. — R. A. Robison.