330 GEOGEAPHICAL AND GEOLOGICAL DISTRIBUTIOK. 



ered form from the Cretaceous deposits of Belgium, the ancestral 

 type of the short nosed modern crocodilians — i. e., the crocodile 

 and alligator. 



BIRDS. 



The principal features connected with the geographical distribu- 

 tion of birds having been discussed in the early part of this work, 

 only the geological distribution of the class will be considered here. 



The earliest known birds are the Archseopteryx, whose remains 

 have thus far been found only in the Solenhofen limestone (Up- 

 per Oolite) of Bavaria, and the Laopteryx priscus, from a nearly 

 equivalent horizon of the Western United States (Wyoming Terri- 

 tory). The latter, which was of about the size of the great blue 

 heron (Ardea Herodias), is apparently a member of the hetero- 

 geneous group designated by Marsh the Odontornithes, or toothed- 

 birds, to which the more remarkable of the American (Middle) 

 Cretaceous birds, Ichthyornis, Hesperornis, and Apatornis, belong. 

 Ornithic remains, with somewhat doubtful relationships, and re- 

 ferred to the genera Graculavus, Laornis, Palaeotringa, and Tel- 

 matornis, have also been obtained from a somewhat higher horizon 

 (Upper Cretaceous) in the Eastern United States (New Jersey). 

 Almost the only clearly determined bird-remains of this period 

 occurring in Europe are those of Enaliornis (Pelagomis; Upper 

 Greensand of Cambridge), which appears to have had some resem- 

 blance to a penguin. 



In the Tertiary deposits remains of this class are very much 

 more numerous, and there is a close approximation to modern type- 

 structures. Thus, in the Eocene deposits of the Paiis Basin and 

 elsewhere in France (Auvergne, Provence, Languedoc) we find the 

 remains of the true quail (Coturnix), grouse (Tetrao), cormorant, 

 godwit, rail, sandpiper, nuthatch, and falcon, associated with which 

 are a number of forms whose relationships have not in all cases 

 as yet been absolutely determined. The most remarkable of these 

 is probably Gastornis Parisiensis, a bird of about the stature of the 

 African ostrich, but possessing so many well-marked anatine char- 

 acters as to have induced some naturalists to class it with the 

 ducks and geese.* Agnopterus and Elornis appear to have repre- 



* G.istornis Klaasseni, a tird apparently exceeding the ostrich in size, has 

 recently been described by Mr. Newton from tlie Lower Eocene stiata of 

 Croydon, En^dand ("Proc. Geol. Assoc.," Feb., 1886). 



