FALCONID.E — THE FALCONS. 



159 



Subgenus TINNUNCULUS, Vieillot. 



Tinnunculus, Vieill. 1807. (Type, Falco tinnunculus, Linn. Tinnunculus alaudarius, 



Gmel.) 

 ? Tichornis, Kaup, 1844. (Type, Falco cenchris, Naum.) 

 Pmcilornis, Kaup, 1844. (Type, Falco sparverius, Linn.) 



The characters of this subgenus have been sufficiently defined in the 

 diagnosis on page 1427, so that it will be necessary for me only to add a 

 few less important ones. 



The subgenus Tinnunculus is one which is well characterized by pecu- 

 liarities of manners and habits as well as by features of structure. The 

 species are the most arboreal of the Falcons, and their curious habit of poising 



53198,^. 



53198 , ^ . N JlX 



33198 .%. 



Tinnunculus sparverius. 



in a fixed position as they hover over some object of food which they are 

 watching is probably peculiar to them, and has Ijeen remarked of the Old 

 World as well as of the American species. In their structure they are the 

 most aberrant members of the subfamily belonging to the Northern Hemi- 

 sphere and in their weak bill and feet, lengthened tarsi, obtusely tipped 

 quills, more rounded wings, and more lengthened tail, exhibit a decided step 

 toward H icracidea, an Australian genus which is almost exactly intermediate 

 in all the characters of its external structure between tlie true Falcons and 

 the South American genus Milvago, of the Polyborine group. 



The subgenus is most largely developed in the Old World, where are 

 found about a dozen nominal species, of which perhaps one half must be 



