1894.] IN THE BRITISH MUSEUM. 121 



usual, but show scarcely any curvature from above downwards. 

 There is, moreover, a lateral fossa in the centrum separated from 

 that in the arch by a nearly horizontal plate of bone. 



The specimen which agrees most closely with the first of the 

 larger ones just described has a centrum measuring 4 cm. long, 

 3 cm. high, 2-5 wide in the middle. 



Another specimen gives the following measm*ements : — 



cm. 



Length of centrum 3-5 



Height of centrum at hinder end 2-7 



Width of centrum in middle . . . .• 2-0 



From the above descriptions it will be seen that the ^pyornithid^e 

 must have included a large number of forms differing greatly in 

 size and proportions ; indeed, in a very recent paper (4) Milne- 

 Edwards and G-raudidier have given names to no less than seven 

 new specie.s, tlu-ee of which are referred to a new genus, Muller- 

 ornis, and it seems probable, as was shown above, that a third genus 

 at least will have to be established. It is to be hoped that the 

 authors just mentioned have taken some particular bone as the 

 type specimen of each species, and that names have not been 

 given to miscellaneous collections of conjecturally associated bones. 

 If it should unfortunately prove tliat this precaution has been 

 neglected, then it seems probable that confusion in the nomen- 

 clature of the ^pyornithidfe will result. 



It is greatly to be desired that collectors should, whenever 

 possible, mark in some distinctive manner such bones as occur 

 together and appear to have belonged to one individual \ But 

 even when this is not done, it is still possible to avoid confusion 

 to a large extent by applying specific names to some definite bone, 

 preferably the metatarsus, as the type specimen of the species. 



The Affinities of ^pyomis. 



Concerning the affinities of ^pyornis the most divergent views 

 have been held. Isidore Geoffroy in his original paper (6) referred 

 it to the Brevipennes (Eatitae), an opinion now universally accepted. 

 Valenciennes (9) considered it to be a diving bird, related to the 

 Auks and Penguins. Bianconi (1) in a long series of papers strove 

 to show that ^pyornis was the " Eoc " of Eastern fable, and that 

 its nearest living relative is the Condor. Milne-Edwards and 

 G-randidier (3) confirmed Geoffrey's original opinion and considered 

 that Gasuarius and Dinornis are the nearest allies. Von Haast (7), 

 on the other hand, opposed this view and asserted that the resem- 

 blances with Dinornis are superficial. Eecently this opinion has 

 been endorsed by Eiirbringer (5) and E. Burckhardt (2), both of 

 whom, after an elaborate comparison of the ^pyornithidje with 

 the other Eatite famiUes, come to the conclusion that such resem- 

 blances as exist between u^pyomis and Dinornis are merely the 



' In the present instance this appears to have been out of the question, the 

 bones occurrixig scattered at random. 



