DENTIROSTRES. 77 



notch is confined to the horny exterior of the 

 beak, no trace of it being to be discovered in the 

 bone, from which, on the contrary, the tooth in 

 the beak of the Falcons is a true process. In 

 other Families, the notch becomes very small, so 

 as at length to be scarcely perceptible ; and, in 

 fact, the transition from this Tribe to the Tenui- 

 rostrrs on the one hand, and to the Conirostres 

 on the other, is so gradual that the points of 

 separation cannot be determined with precision. 



HEAD OF TYRANNUS. 



The food of the birds of this Tribe consists 

 very largely of insects, though not a few combine 

 with this diet, berries and other soft fruits. None 

 of them feed on hard seeds, which constitute the 

 principal support of the Conirostres. With the 

 exception of the single Family of the Finches 

 (Fringilladce) in the Tribe just mentioned, almost 

 all the birds that possess musical notes are found 



