17 



R. W. Shufeldt, U. S. A., one of our most eminent avian anato- 

 mists. 



Professor Marsh published, in 1880, an elaborate memoir on 

 the toothed birds, under the title "Odontornithes : a Monograph 

 on the Extinct Toothed Birds of North America," a large quarto 

 volume, illustrated with thirty-four large plates and numerous 

 wood cuts. 



Eurhipiditne. — The fourth Subclass, Eurhipidurce (fan-tailed 

 birds), comprises all living birds, together with some extinct forms, 

 and is divided into numerous orders and families. The " lowest," 

 or least specialized, is 



Order I, Struthiones, consisting of the Ostriches, Rheas, Casso- 

 waries, Emeus, and Moas. The birds of this order are especially 

 remarkable for the great development of their legs and the rudi- 

 mentary condition of their wings. They are preeminently walk- 

 ing birds, and are also incapable of flight, their wings merely 

 aiding them somewhat in running. The wing muscles are thus 

 rather slightly developed, and there is no keel to the sternum, 

 which is merely a flat buckler, as shown in the skeleton of the 

 Rhea, or South American Ostrich, in Case K. The Struthious 

 birds belong to a waning type, and are now confined to the 

 southern continents, though formerly inhabiting Europe and 

 North America, where the fossil remains of several extinct species 

 have been found. The Ostriches (family Strut/iionidce) are con- 

 fined to Africa, and until recently were all considered as belong- 

 ing to a single species {Strut/iio camelus)^ represented in Case K. 

 Two other forms have been recently recognized, but the differ- 

 ences are slight and of doubtful importance as specific characters. 

 Ostriches live in small flocks, are exceedingly wary, and rely on 

 their keen sight and extreme fleetness of foot to escape their 

 enemies. 



The Rheas or Nandus (family Rheidce) are the so-called Ostriches 

 of South America. They are much smaller than the true Ostriches, 

 have three toes instead of two, and lack the beautiful plumes 

 which have made the African Ostriches so much admired, and 

 which have finally led to their domestication and introduction into 

 Buenos Ayres, California, and other parts of our own country for 



