61 6 CHORD AT A. 



Sub Order V. SCANSORES. The climbing birds are readily recog- 

 nized by their zygodaotyle feet (fig. 643, g), in which two toes (2 and 3) 

 are directed forwards, the other two {1 and i) backwards. The forms 

 united under this head differ much in structure and their association does 

 not rest on blood-relationship. 



Section I. Cuouliformes. The Psittaci, or parrots, arc brightly colored 

 mostly tropical birds with short, high, compressed, and strongly bent beak 

 and fleshy tongue. But one species {Conurus carolinenids*) in the United 

 States. Cacatua, Pliclolophus, cockatoos; 3Ielopsittacus, Psittacus, parrots. 

 CucuLl, bill slightly arched or straight ; outer toe usually versatile ; 

 Cucidus, Coccygus,* cuckoos. Section II. Picael'E. The woodpeckers 

 have a long, straight, conical beak and long, protrusible tongue; Picus* 

 Nearly allied are the toucans {Rhamphastos) of the tropics. 



Sub Order VI. PASSERES. This is by far the richest in species of all 

 the groups of birds. They are altrices of moderate size, with slender feath- 

 ered tarsi and strong, horny beak without cere. Of the three anterior 

 toes the two outer are either united or separated to the base (fig. 643, 6), 

 while the hind toe is at a level with the rest. In some, which are usually 

 but not invariably noticeable for the powers of song of the males, there 

 are special muscles to the syrinx which are lacking in other birds. These 

 are called Oscines, in contrast to the other Passeres, the crying birds, or 

 Clamatores. These groups are further distinguished by a large, freely 

 movable hind toe in the Oscines, while in the Clamatores it is restricted 

 in its motions. 



Section I. OSCINES. All our song birds belong here: Feixgillid^, 

 finches; Passer domesticus* English sparrow; ioa;2a,* crossbills ; Icter- 

 ID^ ; Icterus,* orioles ; DoUchonyx, bobolink; Alaudid.e, Alauda* sky- 

 lark ; Sylvicolid^, Dendrceca* Helmintliophaga , warblers; Turbid-E, 

 Tardus* thrushes; Siala* bluebirds; HiRUNDiNiDiE, Hirundo* swallows; 

 Troglodytid^, wrens ; Corvid^, Corvus* crows ; Cyanocitta* jays. 

 The ParadiseiDjE, or birds of paradise, with marked sexual dimorphism, are 

 closely related to the crows (fig. 15). Section II. CLAMAT(3RES. Hereare 

 frequently included a few groups (Cotingid^e, Tyrannid.e) best developed 

 in South America and the lyre birds (Menurid.e) of Australia. Earlier 

 other forms were regarded as allied, but now are separated as Cypselo- 

 morpha3, or Coraciformes, and united with the owls and Picaria;. Cypsele- 

 DAi; C/icetura* chimney 'swallow,' with adherent feet (fig. 643, c). 

 TrochiliDjE, humming birds, best developed in troi)ical America; Trochi- 

 lus* Caprimulgid.e, night hawks; Aiitrostoinns vociferHS* whippoor- 

 will. Alcedinid^e, kingfishers, Cerylc'* Bucerontid.e, horn bills, tropical. 



Sub Order VII. RAPTORES. The birds of prey are strong birds of 

 considerable size. Tliey have the tarso-metatarsus feathered and four 

 strongly clawed toes of what is termed the raptatorial type (fig. 643, rf). 

 The beak is strong, the upper half, strongly hooked at the tip, extending 

 over the lower. Tliere are two groups recognized which probably are 

 not closely related. 



Section I. FALCONIFORMES. Slender birds with close plumage and 

 extraordinary sight; related structurally to the herons. Cathartida 



