VI PICIDAE 457 



fli US has some dozen fairly uniform green members, relieved by a 

 white, bluish, or black throat. The rump may be crimson or 

 rufous, the rectrices tipped with chestnut, and the bill a mixture 

 of red, black, yellow, or horn-colour, usually with a white line at 

 the base. The range is from Mexico to Guiana and Bolivia. 



Fam. XYIII. Picidae. — The Woodpeckers form a very large 

 Family of scansorial birds with zygodactylous feet, which is so 

 natural that Huxley raised it to higher rank as Celeomorphae, 

 while Parker separated it still further as Saurognatliae. The two 

 Sub-families are (1) Picinac, or Woodpeckers, and (2) lynginae, 

 or Wrynecks. 



Sub-fam. 1. Picinac. — The chief external peculiarities of this 

 section lie in the form of the large head, the neck, and the tail- 

 feathers. The neck is often much compressed, with exceedingly 

 powerful muscles, which, coupled with the strong, wedge-shaped 

 bill, enable the bird to operate with ease and celerity upon the 

 boles and limbs of trees, whence it procures much of its food, and 

 where it excavates a deep hole for the reception of its eggs. The 

 shafts of the twelve tail-feathers, of which the outer pair are very 

 small, are in the ' majority of cases stiff and spiny, and therefore 

 well adapted to keep the body close to the bark while climbing ; 

 parallel cases being those of the Tree-Creeper (Certhia) and the Den- 

 drocolaptinae. The shape of the tail is rounded or cuneate; the wings 

 are moderate and not very much pointed, with ten primaries and 

 from ten to thirteen secondaries. The metatarsus is short, with a 

 single row of anterior scutes; the claws are large, sharp, and curved.^ 



The tongue is excessively long and " worm-like," with horny, 

 barbed tip, and is capable of marvellous protrusion owing to the 

 elongated " horns " of the hyoid apparatus, which in some forms 

 curve round the skull and have their origin near the base of the 

 bill. Facility is thus secured for searching narrow cracks or deep 

 hollows for insects, while the secretion from the large salivary 

 glands secures the adhesion of the objects aimed at. The furcula 

 is U-shaped, the syrinx tracheo-bronchial, the after-shaft rudi- 

 mentary, while neither adults nor young have down at any stage. 



The prevailing colours are green, yellow, black, and white, in 

 various combinations, with spots and bars ; brilliant scarlet being 

 commonly present on the crown and frequently also on the back 



^ The hallux is often abocted, producing a tridactylous, instead of a zygodac- 

 tylous, foot (cf. p. 10). 



