.8,,. RECENT RESEARCHES IN FOSSIL BIRDS. 269 



a totally abnormal type, and larger than any hitherto known, by the 

 side of which the moas may be regarded as dwarfs. These huge 

 dimensions appear to be supported by the figure of the mandible, in 

 which the portion in front of the vacuity in the side measures more 

 than 10 inches in length; so that the length of the whole lower jaw 

 would probably exceed a foot. The tip of this gigantic mandible is 

 turned upwards, somewhat after the fashion obtaining in the Agami 

 {P Sophia) and Chauna (Dicholophns) of South America. Professor 

 Ameghino admits that he is unable to assign a definite systematic 

 position to the bird to which these remains pertained. 



In the finely-illustrated folio memoir standing seventh on our Hst, 

 MM. Moreno and Mercerat, of the Museum of La Plata, give us 

 figures of the bones of a large number of these gigantic extinct 

 flightless birds, from the Lower Tertiaries of Argentina, which are 

 referred to no less than nine distinct genera. 



The largest of the birds described by MM. Moreno and Mercerat 

 is designated Byontomis, and has a tibia measuring 30-5 inches in 

 length. Although a bird with such a leg-bone is indisputably entitled 

 to be called gigantic, yet such dimensions scarcely bear out Professor 

 Ameghino's assertion that, by the side of these South American 

 birds, the moas were but dwarfs, when we bear in mind that the 

 largest moa has a tibia of upwards of 39 inches in length. The 

 whole of these birds are referred to a new order, designated Stereor- 

 nithes, said to be alHed to the Anseres (Ducks and Geese), 

 Herodiones (Storks and Herons), and Accipitres (Diurnal Birds of 

 Prey). In our own opinion, these so-called Stereornithes were 

 probably allied ta the European Gastornis ; and they serve, in any 

 case, to indicate that, early in the Tertiary period, gigantic flight- 

 less birds were very widely spread over the continents of the world, 

 from which they would appear, in most instances, to have retired, 

 in later epochs, to the security of the larger islands of the warmer 

 regions of the globe. Further light on this subject is thrown by 

 the memoir standing second on our list, which is an especially 

 valuable one, as showing the present state of our knowledge of the 

 fossil birds of Argentina and Patagonia. Among the points calling 

 for special notice, we may mention that the bird described by 

 MM. Moreno and Mercerat as a gigantic stork, under the name of 

 Palaociconia, is really a Ratite ; and the name of Prociconia is conse- 

 quently proposed for the undoubted stork from the cavern deposits 

 of Brazil, which had been referred in the British Museum Catalogue to 

 PalcEOciconia. A new family (Pelecyornithidae) is proposed for a group 

 of birds allied to the American Rheas ; these having been incorrectly 

 referred by Moreno and Mercerat to the Cathartidae. The so-called 

 Stereornithes of the latter writers are definitely included in the 

 Ratitae, and are all referred to the single family Phororhacosidae, 

 with only the two genera Phororhacos and Bvontovnis, in lieu of the 

 host of names we have referred to in our notice of the large memoir. 



