148 Walter Rothschild. 



Oastornis parisiensis Hébert . Meudon, France. 



Gastornis Maasseni E. T. Newton Croydon, England. 



Gastornis edioardsi Lemoine Rheims, France and 



Belgium. 



Bemiornis minor (Lemoine) Rheims, France 



Eocene. 



Here again I must digress for a moment and urge my hearers 

 not to think, that because I unite all these more ancient forms 

 under the head of Heterornithes, I mean to assert that they are 

 nearly related to one another. I merely wished to imply that all 

 these birds were fore-runners or ancestral forms of the Ratite 

 section of the Palaeognathae. The most nearly pure Ratitae 

 among these birds are M esemhriornis, Ereri%opezus and Psamm- 

 ornis: the former is directly related to the genus Bhea while the 

 latter two appear to be ancestral forms combining the characters 

 of Struthio and Aepyoriiis. 



It Avill be seen that by far the larger number of species of 

 Heterornithine birds inhabited Europe, but although Struthio 

 chersonensis and Struthio Jcaratheodoris inhabited Europe in 

 Pliocene times it does not at all follow that our modern Ratite 

 Palaeognathae originated in Europe on indeed are directly 

 descended from any of the Heterornithes. It is however 

 somewhat significant that representatives of living struthious 

 genera should be found in the region where the remains of the 

 largest number of Heteornithine species occur, though actually 

 no living species is in existance. 



Diatryma from New Mexico judging by its tarso-metatarsus 

 was undoubtedly the most gigantic of the ancient forms, equalling 

 in size the largest Aepyornis and Dinornis. 



Gastornis includes birds at least as big as an Ostrich; they 

 had large heads Avith toothed mandibles, small undeveloped wings, 

 and very powerful legs. Some systematists have placed these birds 

 among the Anserine birds, while Owen saw in them near allies 

 of the Gruiformes. It is however quite clear that ancient Eocene 

 forms, even if closely allied to the Ratitae would still have retained 

 many primitive characters which in Pleistocene and living forms 

 would either have been lost altogether or changed beyond 

 recognition. 



This is the necessary corollary to the assumption, to which 

 I completely subscribe, that the modern Ratitae have been evolved 

 from a form or forms capable of flight. This being so, surely 

 furcula, coracoid, and wings in the forms of the Eocene period 

 would not have been as aborted as in modern Ratitae. It is just 

 these 3 elements of the skeleton which induced Hébert, Milne- 

 Edwards and many others to consider Gastonvis and Bemiornis 

 neatly allied to the New Zealand anserine and flightless Cnemi- 



