Note 152 — Chapter XXXII · THE CLASS OSTRACOPHORI[152]

This group was first called by Cope Ostracodermi—a name preoccupied for the group of bony trunkfishes, Ostracidæ. The still earlier name of Placodermi, chosen by McCoy (1848), was intended to include Arthrodires as well as Ostracophores. Rohon (1892) calls the group Protocephali, and to the two orders he assigns the names Aspidorhini and Aspidocephali. These groups correspond to Heterostraci and Osteostraci of Woodward. Another name of early date is that of Aspidoganoidei, given by Professor Gill in 1876, but not defined until 1896. These fishes are, however, not "Ganoids" and the name Ostracophori seems to receive general preference. The group Peltacephalata of Patten corresponds essentially to Ostracophori, as does also the order Hypostomata of Gadow.