VERTEBRATA (CHORDATA). 



105 



pgedia Anat. and Phys., 1836 ; Selenka, Aves, Bronn's Klassen und Ord- 

 nungen des Thierreichs, 1869-82 ; Huxley, On tJie Classification of Birds, 

 Proc. Zool. Soc., 1867 ; Tiedemann, Anatomie und Naturgeschichte der 

 Vo'gel, Heidelberg, 1848 ; Eyton, Osteologia Avium, London, 1858-60 ; 

 Macgillivray, History of British Birds, 1839-41.) 



SUB-CLASS III. *SAURORNITHES. 

 ORDER. SAURUR./E. Archceopteryx. 



SUB-CLASS IV. *ODONTORNITHES. 



ORDER I. ODONTOLC^E. Hesperornis. 



ORDER II. ODONTOTC-RJVLE. Ichthyornis, Apatornis. 



(Owen, Archceopteryx macrura, Phil. Trans., 1863 ; Carl Vogt, Archceop- 

 teryx, Revue Scientifique, 1879 ; Marsh, Jurassic Birds and tlieir Allies, 

 Rep. Brit. Ass., 1881 ; Marsh, Odontornithes, a Monograph of the Extinct 

 Toothed Birds of North America, New Haven, 1880.) , 



Fig. 93. Odontornithes. Skeleton of Hesperornis regalis, restored, (After Marsh.) 

 About one-tenth of the natural size. 



