128 PEOF. OWEN ON AEG1LLOENIS LONGIPENNIS. 



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 flight- 

 less 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 palaeontologist 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, Liihornis vulturiyius f, at once re- 

 moves that genus and species to a distance from Argillomis. 



The humerus of Pelagornis mioccenus, Lartet J, of similar size to 

 that of Argillomis, 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 bor- 

 der of the shaft ; the ulnar tuberosity is large and projects anconad. 



Prof. Seeley§ refers an ornitholite in the Woodwardian Museum 

 to the Liihornis 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 Struihionidaz 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 Megalomis. 



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 Megalomis, 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 Megalomis for a genus of Birds in 

 his ' List of Genera ' &c." To this notice the Editor adds a foot- 



* Trans. Zool. Soc. vol. vi. p. 144. • 



t ' British Fossil Mammals and Birds,' 8vo, 1846, p. 549, fig, 232. One of 

 the fossils described in the present paper had a label attached, with the name 

 Liihornis emuinus ; if the specific name referred to Dromaius, the evidence of 

 the size of wing and concomitant power of flight renders the reference of such 

 fossil (' Comptes Rendus de l'Acad. des Sciences,' 6 Avril, 1857) to the Austra- 

 lian struthious genus inappropriate. 



| Alph. M.-Edwards, ' Oiseaux Fossiles de la France,' 4to, 18(58, pi. xlv. 



§ Seeley, " Note on some new Genera of Fossil Birds in the Woodwardian 

 Museum" (Annals and Magazine of Natural History, 1866, 3rd ser., vol. xviii. 

 p. 110). '* 



