Order IV. ZYGODACTYLI. 



The second order of Picarian birds comprises the Indicators or 

 Honey-guides, the Barbets, and the Toucans (Rliampliastida?}, the 



last being peculiar to South America, 

 All of these have zygodactyle feet 

 like Woodpeckers, with the first 

 and fourth toes directed backwards, 

 and the picine arrangement of the 

 deep plantar tendons, the flexor 

 perforans digitorum running to the 

 third toe only, whilst the first, 

 second, and fourth toes are sup- 

 plied by branches of the flexor 

 lonyus hallucis, as shown in the 

 accompanying figure by Garrod. 

 The muscles of the thigh, too, in 

 the present group, present the same 

 arrangement as in Pici ; the spinal 

 feather-tract is similarly disposed, 

 the oil-gland is tufted, and there 

 are no ca?ca. The nidification, too, 

 is similar. 



On the other hand, the vomer in 

 the present group, instead of being 

 represented by a number of paired 

 rods, is single and bifurcate, and 

 the palate is either truly desmo- 

 gnathous, the maxillo - palatines 

 blending across the middle line, or 

 segithognathous. The sternum, too, 

 presents some characteristic differ- 

 ences, being much broader, especi- 

 ally in front, in proportion to its 

 length, and the breadth in front 

 being nearly the same as that 

 behind, instead of much less ; the foramina or notches on the 

 posterior border are deeper, the manubrium or rostrum sterni is 

 pointed and not bifid, and the clavicles do not meet to form a 

 furcula. Tongue of ordinary structure, not protrusile. 



The two Indian families of this order are thus distinguished 

 (the characters do not apply to some African forms) : 



Tail-feathers 12 ; primaries 9 Indicatoridae. 



Tail-feathers 10 ; primaries 10 Capitonidae. 



Fig. 22. Tarsus and foot of Mega- 

 IcBma asiatica from behind, dis- 

 sected to show the deep plantar 

 tendons, the /. long, hallucis on 

 the right in the upper part of 

 the figure, the /. per/, digitorum 

 on the left. (G-arrod, P. Z. S. 

 1875, p. 346.) 



