of a Gigantic Bird from Madagascar. 163 



with the eggs. One of them is the lower extremity of the large 

 metatarsal bone of the left side : it has the three trochlear apo- 

 physes ; two of them are even almost untouched. It is enough 

 to cast a glance upon this eminently characteristic piece to re- 

 cognise that it belongs to a bird. Moreover, on examining it 

 with some attention, we soon arrive at the following conclusions. 

 The gi-eat bird of Madagascar differs considerably from the Dodo ; 

 it wanted that greatly developed thumb, by which the large bird 

 of the Mauritius differed from the Struthionians and the Caso- 

 warians ; this we are authorized to conclude from the non-exist- 

 ence, at the bottom of the large metatarsal bone, of the inden- 

 tion which corresponds with the insertion of the thumb in the 

 Dodo and the other birds whose foot presents the same confor- 

 mation. In this point of view, the Madagascar bird approaches 

 the Dinornis ; but it differs from it, as well as from the other 

 allied genera recently discovered in New Zealand, in the very 

 dilated and depressed form of the lower portion (and probably 

 of the greater part) of the metatarsal bone*. 



As for the Ornithichnites, on the one part, and the Ostrich and 

 other allied genera, no one would assuredly be induced to assi- 

 milate them to the gigantic bird of Madagascar, which hence- 

 forth should become the type of a new genus in the group of the 

 Rudipens or Brevipens. We shall give to this genus the name 

 of ^pyornisf, and to our species the epithet of maximus. 



The consideration of the other osseous fragments will confirm, 

 we may already assert, the inductions to which we have just been 

 led by the examination of the great metatarsal — the portion to 

 which we have first directed our attention, as eminently proper 

 to characterize not only the class and order, but even the genus 

 to which the precious fragments transmitted by M. Malavois are 

 to be referred. Such a study will doubtless enable us to discuss 

 (that which we could not as yet do with, advantage) the value of 

 the affinities which connect the ./Epyornis with the various ge- 

 nera of the same group, and to determine with some accui'acy 

 the dimensions of this ornithological giant. Meanwhile, and 

 with a view to answer the questions which have been addressed 

 to us from all quarters, we shall restrict ourselves, on this last 

 point, to some remarks, intended especially to prevent the exag- 

 gerations in which some might be apt to indulge. 



The long diameters, in the eggs of ^pijornis and Ostrich 

 which we have compared, are, in the one case, 33 centimetres, 



* Immediately above the trochlear apophyses, this bone is near 1 deci- 

 metre across, and its thickness scarcely exceeds 3 centimetres A deci- 

 metre higher up, we find 007 metre again for the transversal diameter, 

 and only 00375 for the antero-posterior diameter. 



t Alta or magna avis. From atirvs, tall, large • and opvis. 



11* 



