294 ZOOLOGY. 



3. Natatores, or swimming Birds, of which the Goose and Duck arc 

 familiar examples. They habitually live in the water, for which they arc 

 admirably constructed, like the whales, dolphins, and other aquatic mam- 

 malia to which they are analogous. 



4. Grallatores, or wading Birds, well represented by the common Herons 

 and Cranes. In these birds the long legs and neck are striking charac- 

 ters, and their entire organization has for its object the pursuit of such 

 fishes or other animals as inhabit shallow waters or marshes. 



5. Rasores, or Avalking Birds, represented by the domestic Fowl and the 

 Turkey, by the Pheasants, Partridges, Quails, and other birds. They live 

 almost entirely on the ground, and are almost the only birds which have 

 been completely domesticated. 



We cannot, however, possibly enter into any details of this system, and are 

 sorry to say that it has not been elaborated by any author to such extent as 

 to enable us to avail ourselves of his labors so far as to present a view of the 

 various families of birds upon its basis. The reader can consult with 

 great advantage, upon this subject, the volumes of Lardner's Cyclopaedia by 

 Swainson. 



The publication of '' The Genera of Birds " by George Robert Gray, an 

 ornithologist of great acquirements attached to the British Museum, has 

 })laced in the hands of naturalists the most complete synopsis of the genera 

 and species of birds ever produced. His method and views of classification 

 we propose to adopt in the following pages. 



Gray divides the class of birds into eight orders, as follows : 



1. ArciPiTREs, Rapacious birds. {Pis. 104, 105.) 



2. Passeres, Sparrows, Thrushes, and generally all the small birds. 



( Pis. 99, 100, 101, 102.) 

 o. ScANSoRES, Parrots, Woodpeckers, Cuckoos, (fcc. 

 (Part of pU 97, 98.) 



4. CoLUMB^, Pigeons and Doves. {PI. di^,ßffs. 12 to 15.) 



5. Gallin^e, Cocks. Pheasants, Grouse, Turkeys, &c. 



(Partof ;>/5. 95, 96.) 



6. Struthiones, Ostriches, Bustards, an<l the Emu. 



{PI. M,ßgs. 1, 2.) 



7. Grall.e, or Wading birds. {PL 93.) 



8. Anseres, or Swimming birds. (Pis. 91.92.) 



These orders contain, according to the views of Gray, about fifty families, 

 which are again divided into about one hundred an<l fifty sub-families, admit- 

 ting about eight hvindred genera. 



The number of species of birds known is variously estimated. Gray 

 enumerates in his great work about six thousand species, but Des Murs of 

 ]*aris, in a beautiful and important work the Iconographia Ornithologica, 

 now in the course of publication, and in which he intends to give plates of 

 all known birds not previously figured, estimates them at ten thousand. 

 T^he probability is that there are at this time about seven thousand well 

 determined birds, many of which have been discovered since the commence- 

 Tnent of Gray's work ; and to this number constant and large accessions 

 498 



