178 



NATURAL HISTORY OF BIRDS. 



the introduction (p. 7). The second cut shows very well the graceful plumes of the 

 egrets (Herodias), a group characterized, besides, by slender but elegant proportions 

 and the dazzling whiteness of the plumage. The species here figured is H. alba, of 

 nearly cosmopolitan range, and represented on our continent by a slight race, H. alba 

 egretta. Similarly white, but with the ornamental feathers of the head, breast, and 

 back of a rusty Isabella color, is the buff -backed cattle-egret (JSubidcus ibis), which 

 has already been mentioned as the bird usually shown to the travelers in Egypt as 



Fio. 87. Cochlearius cochlearius, boat-bill. 



the sacred ibis of the ancients. In its rather stout build, short neck, short and strong 

 bill, it approaches the night-herons (JVycticorax), which, besides, are easily recognized 

 by the extremely lengthened linear and compact webbed plumes on the occiput. 



Two authors, each holding a leading position as ornithologist in their respective 

 countries, in 1877 monographed the herons. One of them made the boat-bill (Cochlea- 

 rius, or Cancroma) a sub-genus under the genus JVycticorax, the other regarded it as 

 constituting a separate family, equal in rank to the Ardeidas. It will be seen that the 



