Page:Quarterly Journal of the Geological Society of London, vol. 34.djvu/168

128 remains from the London Clay, the cranial evidence of Dasornis londinensis indicates a bird too big to be upborne by wings of a size to which the present fossil bone would belong; and, besides, the characters of that fossil skull were rather those of a large flightless or ground-bird. The skull of Odontopteryx, on the other hand, seems too small in proportion to the humerus of a bird exceeding in size that in Diomedea.

It is much more probable that the avifauna of the Eocene period should supply a palæontologist with many more species than he has already determined, than that so singular a form should have existed as a bird with a head of the size of that of the Solan goose and wings of vaster expanse than those of the albatross. The sternum of the still smaller Eocene bird, Lithornis vulturinus, at once removes that genus and species to a distance from Argillornis.

The humerus of Pelagornis miocænus, Lartet, of similar size to that of Argillornis, differs, as far as its mutilated state permits comparison, in the form of the articular head and the narrower scapular groove.

In Pelagornis the head is relatively small and less prominent proximally than in other birds; the transverse ligamentous groove (e) is well marked, as in Totipalmates; the bicipital surface is very narrow, and develops below a tuberosity more prominent than in the Boobies (Sula), but not projecting beyond the ulnar border of the shaft; the ulnar tuberosity is large and projects anconad.

Prof. Seeley refers an ornitholite in the Woodwardian Museum to the Lithornis emuinus of Bowerbank, and accepts its supposed emuine or cursorial affinity, with the remark:—"Taking the ostrich as a type, this bird diverges from the typical Struthionidæ on the other side of the emu, yet appears to conform to the Casuarine allies;" and he proposes to refer the fossil to a genus Megalornis.

If the Woodwardian fossil should prove to have formed part of the longipennate volant bird, the subject of the present paper, I would refer to the 'Proceedings of the Zoological Society of London,' February 1843, for the following entry:—"A communication from Prof. Owen was read, proposing to substitute the name Dinornis for that of Megalornis, applied to the Great Bird of New Zealand in his paper read at the previous Meeting. The change is rendered desirable to prevent confusion in nomenclature, Mr. George Gray having previously used the term Megalornis for a genus of Birds in his 'List of Genera' &c." To this notice the Editor adds a