In this paper are described the seven larger arthrodiran fishes from the Lower Devonian strata of the Burrinjuck area in New South Wales. The first is an interesting new palae-acanthaspid, but the six other fishes are euarthrodires remarkable not only for individual peculiarities but for a mixture of characters usually attributed to two or more of the main lines of arthrodiran evolution. They may be considered as early essays in the development of arthrodires, but they also suggest that the main groups were not descended one from another, as for instance the brachythoracids are often said to have evolved from the arcto-lepids, but from a more distant common ancestor.

The development of the apron is demonstrated and the nature of the periophthalrnic capsules in relation to sclerotic plates is discussed.