300 VERTEBRATE ANIMALS. 
loud, harsh, and grating voices. The beak (fig. 163) is hooked, 
and is used as a kind of third foot in climbing, but some move 
about actively on the ground. 4. The Rhamphastide or Tou- 
cans, distinguished by their enormously large and cellular bills, 
the sides of which are serrated. They live in deep forests, in 
small flocks, and are confined to tropical America. 5. The 
Trogonide or Trogons, which inhabit the most retired recesses 
AS 
Fig. 163.—Scansores. Purple-capped Lory (Lovins domicella), 
of the forests of the intertropical regions of both hemispheres, 
and are distinguished by their resplendent plumage. 
ORDER VI. INSESSORES.—The sixth order of Birds is that 
of the Zzsessores or Perchers, often spoken of as the Passerine 
Birds. They are defined by Owen as follows : “ Legs slender, 
short, with three toes before and one behind, the two external 
toes united by a very short membrane” (fig. 164, A, B). 
