On two Chimæroid Jaws from the Lower Greensand of New Zealand

Abstract

H aving been working for some time past at the Cretaceous Fishes, my interest has been especially centred in the group of the Edaphodontidæ; for the specimens belonging to this group, which have been brought to light within the last few years, have much enlarged our knowledge of these peculiar forms of fossil fishes. The general results of my examination of this group, will shortly be published; and in the present communication it is only proposed to consider two specimens from the Lower Greensand of New Zealand, which have been deposited in the British Museum by Dr. Hector. My attention was first directed to these specimens by Mr. W. Davies, of the British Museum, when I was examining the fine series of Chimæroid jaws now in the national collection. One of these New-Zealand specimens is the right mandible of a species of Ischyodus already known to us from the Gault of Folkestone; and the second is a small right maxilla, which is altogether new and appears to be generically distinct from any of the fossil forms hitherto described. Before considering the peculiarities of the mandible, it will be necessary to enter into some explanation and description of the species to which it is referred. It appears that, the late Prof. Agassiz, some years ago, saw in the Earl of Enniskillen's collection of fossil fishes, a Chimæroid mandible from the Gault of Folkestone, which he named, in manuscript, Chim0œra brevirostris. Subsequently, in his ' Poissons Fossfles' (1843), he alluded to this specimen