SUPEK-ORDER iv EUORNITHES 273 



France ; and it is of interest to note that the earliest known auk, MancalJa 

 caUforniensis, from the Upper Miocene of California, was a highly specialised 

 and flightless form. 



Order 3. GRALLAE. 



The Grallae are a group of wading birds having a schizognathous skull with- 

 out basipterygoid processes and schizorhinal nostrils. The order embraces the 

 cranes, snipe, bustards, and rails, and includes an unusual number of aberrant 

 forms, such as the South American trumpeter, PsojMa; the Seriema, Cariama; 

 and the Xew Caledonian Bhinochoeius, birds which retain some of the characters 

 of their ancestral forms, and hence being more generalised than their modern 

 relatives, are hard to fit into any scheme of classification. 



The plovers closely approach the gulls among the Cecomorphae,^ while 

 through Cariama the Grallae point towards the birds of prey, and there is a 

 strong and probably more than superficial likeness between this and the 

 equally aberrant accipitrine secretary bird. 



The gigantic birds of the genus PhororJuicos, and their allies from the 

 Miocene of Patagonia, are gralline birds related to Cariama, although some 

 structural details seem to point towards the herons. They are distinguished 

 by a large skull having a high, compressed, and sharply hooked beak, and by 

 a small sternum and shoulder girdle ; the pubis, save the anterior end, is 

 lacking. The skull of the largest species, Phororhacos longissimus, was 0'6 m. 

 long, and the cervical vertebrae 13 cm. across, far exceeding in their dimensions 

 those of any other bird. Their structure suggests that they w^ere cursorial 

 birds of prey in their habits. These highly specialised forms are from the 

 Santa Cruz beds of the Miocene of Patagonia. It is probable that Diatryma 

 from New Mexico is related to these birds. A crane, Palaeogrus, occurs in 

 the Eocene of Italy ; and another, Aletornis, in the Eocene of Wyoming. A 

 rail, Gypsornis, is found in the Eocene of Montmatre. 



Order 4. CHENOMORPHAE. 



The Chenomorphae, or ducks, after excluding one or two debatable species, 

 form a sharply defined group of water-birds, whose skull is typically desmo- 

 gnathous, either by the direct fusion of the maxillo-palatines or their indirect 

 union through the ossified narial septum. Low basipterygoid facettes are 

 present, well forward on the sphenoid, and on these the pterygoids slide, 

 allowing a slight motion of the beak. The posterior end of the mandible is 

 produced and recurved. 



The "outliers" of the Chenomorphae are three species of South American 

 birds representing the genera Palamedea (or Anhima) and Chauna, which form 

 either a separate order, sub -order, or superfamily, the Palamedeae. These 

 birds have neither webbed feet nor duck-like bills, and bear a slight superficial 

 resemblance to the fowls, although anatomical characters place them near 

 the ducks. 



The flamingoes form another debatable group, assigned by some to the 



^ That Beddard includes both gulls and plovers in his Liiaicolac may serve as an illustration 

 of the slight variations among birds, and the extent to which individual opinion enters into the 

 classifying of birds. 



VOL. II T 



